Crop Residue Burning Research Papers (original) (raw)

In southwestern region of Punjab in north India, sowing dates of cotton crop in cotton (Gossypium hirsutum L.)-wheat (Triticum aestivum L.) system are staggered from last week of April to mid of May depending upon the surface water supply from canal as ground water is not fit for irrigation. Further, farmers practice intensive cultivation for seedbed preparation and burning of wheat straw before sowing of cotton crop. With the present farmers' practices, yields have become static and system has become nonprofitable. Field experiments were conducted on Entisols for two rotations of cotton-wheat system during the years of 2004-2005 and 2005-2006 in split plot design to study the direct and interactive effects of date of sowing and tillage-plus-wheat residue management practices on growth and yield of cotton and wheat and to increase the profitability by reducing the tillage operations, which costs about 50% of the sowing cost. The pooled analysis showed that in cotton crop, there was a significant interaction between year Â dates of sowing. Among different tillage-plus-wheat residue management practices yields were 23-39% higher in tillage treatments than minimum-tillage. In wheat, grain yield in tillage treatments were at par. Water productivity amongst the tillage treatments in cotton was 19-27% less in minimum tillage than others tillage treatments. Similar trend was found in wheat crop. Remunerability of the cotton-wheat system was more with a combination of reduced tillage in cotton and minimum tillage in wheat than conventional tillage. #

- by and +1
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- Biological Sciences, Environmental Sciences, Forest Growth and Yield, Ground Water

- by Christine Moureaux
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- Earth Sciences, Climate variability, Biological Sciences, Eddy Covariance

Experiments were carried out to compare the direct approach for estimating crop N uptake from 15 N labelled organic inputs, to two indirect approaches, 15 N isotope dilution and A value. In the first experiment soils received 25, 50, 75, or 100 mg N kg soil −1 in the form of Casuarina equisitifolia residues in addition to ammonium sulphate fertiliser, to give a total of 100 mg N kg soil −1 added. This was a cross labelling design, thus two matching sets of treatments, were set up, identical in all but the position of the 15 N label. Maize (Zea mays L.) plants were grown in the soils amended with residues for 11 weeks and N derived from residues (Ndfr) estimated using the A-value or the direct approach. The A-value approach appeared to significantly overestimate %Ndfr compared to the direct method. In the second experiment contrasting residues were added to soil, fababean (Vicia faba L. var. minor), alfalfa (Medicago sativa L.), soyabean fixing, (Glycine max (L.) Merrill), soyabean non-fixing, barley (Hordeum vulgare L.) and maize. This was also cross-labelling design, labelled and unlabelled residues were used. Maize plants were grown in these soils for 11 weeks and %Ndfr in the maize plants estimated using 15 N isotope dilution and the direct approach. The 15 N isotope dilution approach also overestimated %Ndfr compared to the direct method in this experiment. Pool substitution appeared to be responsible for the discrepancy between the direct and indirect techniques. It was concluded that 15 N isotope dilution and A-value approaches as used in these experiments (i.e where residues and 15 N label are added simultaneously) were not appropriate techniques for estimating N derived from organic residues in soils.

- by Rebecca Hood-Nowotny
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- Biological Sciences, Environmental Sciences, Maize, Nitrogen
- by Rainer Zah
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- Engineering, Energy demand, Crop Residue Burning, Energy Crop

A field survey in Prunus armeniaca growing areas of Garhwal Himalaya was conducted with reference to the germination and growth of some companion crops at various sites of different soil fertility. Retardation in germination, growth and yield were noted in nearby ¹riticum aestivum plants, particularly on those sites where the percentage of soil organic matter was low. It was also observed that the magnitude of interference gradually decreased as the distance from the tree increased. Aqueous and organic solvent extracts of the aerial parts of Prunus armeniaca were made and their residues were tested, after proper dilution, for their phytotoxic effect on germination and growth of the test crop. Residues of light petroleum and ethyl acetate extracts showed maximum inhibition in growth and germination of the test species. The isolated compounds were identified with the help of spectroscopic techniques and bioassays. -Sitosterol, 2,6-dihydroxy-4-methoxyacetophenone and kaempferol were isolated from a petroleum extract whereas aromadendrin, quercetin, -sitosterol--D-glucoside, pleoside and tannins (four proanthocyanidins -A-type) were characterized from an ethyl acetate extract. Of these, proanthocyanidins showed maximum inhibition, whereas quercetin, aromadendrin, kaempferol and genin of pleoside inhibited to a lesser extent.

- by DEVI RAWAT
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- Technology, Allelopathy, Biological Sciences, Triticum Aestivum

Catch crops can effectively decrease nitrate leaching in arable cropping systems but their longterm impacts on nitrogen mineralization are not well known. This study quantified the effects of continuous catch crops on net N mineralization, crop N uptake, crop N use efficiency and N leaching in three long-term (13-17 years) field experiments in northern France. Mustard was grown every year at Boigneville, radish every year at Thibie and ryegrass every 2 years at Kerlavic. The mean N content of catch crop residues at these sites was 33, 36 and 35 kg ha −1 yr −1 and their mean C:N ratio was 13, 17 and 28, respectively. Net mineralization was calculated with a mass balance of soil mineral N using measured inputs and outputs. Catch crop establishment enhanced annual mineralization by on average 26, 18 and 9 kg N ha −1 yr −1 respectively during the 13-17 year period. The difference in mineralization rate between catch crop and control treatments (extra mineralization) was positive from the first year at Boigneville, whereas it was negative or nil during the first 3-5 years at Thibie and Kerlavic. At the latter sites, the extra mineralization rate increased significantly over time at a rate of 2.0 and 2.6 kg N ha −1 yr −2 . At the end of the experiment, cumulative extra mineralization represented 72%, 60% and 23% of the total N added by catch crop residues at Boigneville, Thibie and Kerlavic, respectively. Repeated catch crops significantly increased N uptake and N use efficiency by main crops at Kerlavic and Thibie, but not at Boigneville. The efficiency of catch crops in reducing N leaching persisted over the years at all sites. A model simulating C and N dynamics during catch crop decomposition was able to reproduce the pattern of extra N mineralization kinetics with the various catch crop species, but underestimated the range of variation between sites. Better predictions were obtained when C or N inputs due to catch crops were increased by 10-57%, suggesting that the actual inputs could be markedly greater than those measured in catch crop residues. According to the model, the C: N ratio of catch crop residues largely explained differences in mineralization due to different catch crop species.

- by Nicolas Beaudoin
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- Kinetics, Biological Sciences, Environmental Sciences, Field Experiment

Eddy covariance measurements of CO 2 fluxes were conducted in 2004 at the agricultural site of Lonzée, Belgium, over a sugar beet crop. Additional measurements of biomass net primary production and leaf area index (LAI) were carried out. The response of the fluxes to climatic and non-climatic variables was analysed. Nighttime fluxes were dependent on turbulence, temperature and high soil water content. The u * correction was determined using a statistically based algorithm. The lower u * threshold was 0.1 m s À1 . Daytime fluxes during maximum canopy development depended mainly on incident radiation and its repartition between direct and diffuse components. A limited response to saturation deficit and soil water content was also observed. The evolution of assimilation and respiration throughout the growing season was studied. Maximum assimilation fluxes were observed in July when canopy had not fully developed and these then decreased from the end of July to the harvest, due not only to a reduction in radiation but also to a reduction in canopy assimilation capacity. Normalised respiration evolution presented two peaks during the year: the first in July, when the assimilation was at its greatest, and the second after the harvest, during the crop residues decomposition. The annual sequestration, estimated by half-hourly flux summing and measurement gap filling, was À0.61 AE 0.11 kg C m À2 and the impact of the u * correction and of the residues decomposition was estimated to be 5.3 and 3.5%, respectively.

- by Bernard Bodson
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- Earth Sciences, Climate variability, Biological Sciences, Eddy Covariance
- by Vijaya Raghavan
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- Waste Management, Multidisciplinary, Anaerobic Digestion, Case Study

Background, Aim and Scope. Soybean meal is an important protein input to the European livestock production, with Argentina being an important supplier. The area cultivated with soybeans is still increasing globally, and so are the number of LCAs where the production of soybean meal forms part of the product chain. In recent years there has been increasing focus on how soybean production affects the environment. The purpose of the study was to estimate the environmental consequences of soybean meal consumption using a consequential LCA approach. The functional unit is 'one kg of soybean meal produced in Argentina and delivered to Rotterdam Harbor'.

- by Mikkel Thrane and +1
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- Environmental Engineering, Life Cycle Assessment, Global Warming, Building

Agricultural straw Hordeum vulgare L Brassica napus Avena sativa Triticum aestivum a b s t r a c t

- by Sudhagar Mani and +1
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- Engineering, Technology, Triticum Aestivum, Crop Residue Burning

The nutritive value for ruminants of postharvest bean (Phaseolus vulgaris L.) stem, leaf and empty pod by-products were studied in adult male goats. In vitro, potential and effective ruminal degradability of organic matter were, respectively, 55.4%, 57.0% and 30.6% for stems, 81.5%, 79.6% and 64.6% for leaves, and 67.2%, 86.2% and 49.8% for pods. The energy content of the by-products was estimated to be 9.2 MJ ME kg−1 DM stems, 8.5 MJ ME kg−1 DM leaves, and greater than 9.9 MJ ME kg−1 pods. The by-products contained 55 g of degradable and 28 g undegradable protein kg−1 DM stems, 142 g and 60 g kg−1 DM leaves, and 29 g and 13 g kg−1 DM pods.

- by Mj Flores
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- Animal Production, Crop Residue Burning, Organic Matter, Nutritive Value

One of the major interests in soil analysis is the integrated evaluation of soil properties, which might be indicators of soil quality. Unsupervised methods of multivariate statistics are powerful tools for this integrated assessment and can help soil researchers to extract much more information from their data. A multivariate study was carried out in three farms from Guaíra, State of São Paulo, Brazil. Conventionally managed plots that intensively utilized pesticides and chemical fertilizers were compared with both non-disturbed forest areas and alternatively managed plots. The latter were under ecological farming employing effective microorganisms (EM) integrated with crop residues. Eight soil parameters were determined for each plot. Hierarchical cluster analysis (HCA) was used to verify the similarity among the plots. The multivariate approach of principal component analysis (PCA) allowed us to distinguish the areas as a function of the soil management and determine which are the most important parameters to characterize them. The forest areas presented higher microbial biomass with lower cellulolytics population than at cultivated sites. The alternative plots were characterized by higher microbial biomass and polysaccharide content with lower phosphate solubilizers and cellulolytics microorganisms colony counts than at the conventional areas. The higher observed levels of microbial biomass and polysaccharide content in the alternative areas can be attributed to the effects of the alternative soil amendment. All these effects can be clearer globally visualized with the aid of PCA, through the biplots.

- by Marcelo Martins Sena and +1
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- Multivariate Statistics, Principal Component Analysis, Integrated assessment, Soil Analysis

Acquisition of soil and fertiliser phosphorus (P) by crops depends on soil and plant properties. Soil processes determining P availability to plants are P solubility/sorption, P transport, root/soil contact and mineralisation/immobilisation. Plants have evolved properties contributing to a more efficient use of plant-available soil P and to mobilise P from less available soil P fractions. Agronomic measures may affect P availability to crops through the modification of soil properties or through direct quantitative and qualitative crop impact on soil P dynamics. Among the agronomic measures, the application of organic matter such as green manure and crop residues to maintain or increase soil organic matter content and to enhance soil biological activity, and the incorporation into the cropping system of P-mobilising plant species are particularly beneficial.

- by Prof. V.O.Chude
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- Biological Sciences, Phosphorus, Environmental Sciences, Maize
- by Bijay Singh
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- Agronomy, South Asia, Plant Biology, Clay Minerals

For grain crops, harvest index (HI) is the ratio of harvested grain to total shoot dry matter, and this can be used as a measure of reproductive efficiency. The index can also be used to estimate crop carbon (C) balances by applying it to grain yield statistics to determine total shoot dry matter and then calculating crop residues as the difference between shoot C and grain C. Such an approach is widely used in C-accounting systems. Such a C-accounting practice is sensitive to changes in HI. In Australia, measured variations in HI are large enough to alter C balance calculations for some crops. Much of this variation results from the diverse range of climates and soils, which are a feature of the Australian cereal cropping region.

- by Murray Unkovich
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- Agronomy, Seasonality, Nitrogen, Crop Residue Burning

Sustainable agricultural management is essential not only to maintain productivity of current farmlands, but also to conserve natural environments. Records of agricultural activities are required to assist rapid assessment of agricultural lands, and thus, designation of management plans and policies. By the 1980s, when unfavorable environmental impacts of conventional tillage practices were widely recognized, agronomists introduced conservation tillage to benefit soils and agricultural environments, and soon began programs to monitor adoption of conservation tillage practices. The role of remote sensing in acquiring this information has been increasing because remote sensing technologies can provide the broad scope and the ability to collect sequential imagery to estimate trends and patterns of adaption of alternative tillage practices. This review encompasses comparisons of remote sensing techniques with more conventional methods for surveying and estimating tillage status, applications of remote sensing technologies, data processing and analysis, validation and field data collection, impacts of terrain, spectral and spatial resolution, timing and temporal detail, and prospects of future instruments.

- by John Galbraith
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- Remote Sensing, Agriculture, Biological Sciences, Environmental Sciences

The most common approach to biological control consists of selecting antagonistic microorganisms, studying their modes of action and developing a biological control product. Despite progress made in the knowledge of the modes of action of these biological control agents (BCAs), practical application often fails to control disease in the fields. One of the reasons explaining this failure is that the bio-control product is used the same way as a chemical product. Being biological these products have to be applied in accordance with their ecological requirements. Another approach consists of induction of plant defence reactions. This can be done by application of natural substances produced by or extracted from microorganisms, plants, or algae. Since they do not aim at killing the pathogens, these methods of disease control are totally different from chemical control. Although promising, these methods have not been sufficiently implemented under field conditions. A third approach consists of choosing cultural practices that might decrease the incidence or severity of diseases. These methods include the choice of an appropriate crop rotation with management of the crop residues, application of organic amendments and the use of new technology such as the biological disinfestation of soils. Biological control practices need an integrative approach, and more knowledge than chemical control.

- by Claude Alabouvette
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- Microbiology, Natural Products, Plant Biology, Ecology

Controlled study was conducted with five farm-based organic residues to predict the expected nitrogen availability with time, based on N concentration and C/N ratio of the residues under two moisture availability situations. Two kg of red loamy sand soil representing Alfisol and related soil was incubated with the residues to supply 40kgNha-1 at 28_+ I°C at field capacity (FC) and 50% FC moisture conditions. Results obtained indicated that N content in soil released from residues increased with the time allowed for decomposition reactions at both FC and 50% FC moisture regimes. Relatively higher amount of N release was observed in case of legume residues like mungbean (Vigna radiata), L. leucocephala and perennial pigeonpea (Cajanus cajan), although the rate of N release was more with low N concentration residues. Sorghum stover with C/N ratio of 72.1 resulted in immobilization of N upto 90 days. Nitrogen release was higher at FC than 50% FC. The critical N concentrations of the residues at which N neither released nor immobilized decreased with the length of incubation. At 50% FC the critical concentrations were higher than at FC.

- by Bandi Venkateswarlu
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- Analytical Chemistry, Nutrient Cycling, Sorghum, Nitrogen

Advances in laboratory instrumentation and chemometrics provide alternatives to traditional methods of conducting soil chemical analysis. One of these is infrared diffuse reflectance spectroscopy in the near-infrared spectral range (NIRS). Herein we report the results of a multinational study to develop useful calibrations associating NIRS spectra with laboratory-measured results for total soil carbon (C), total soil nitrogen (N), δ13C, and δ15N from a single soil site in Mexico subjected to zero- and conventional-tillage regimens with and without crop residues and crop rotations of maize and wheat across 16 years. Modified partial least squares regression (MPLS) was used to obtain useful NIR predictions for total soil C and N, with ratio performance deviation (RPD) values of 6.8 and 2.6, respectively. Corresponding multiple correlation coefficients (RSQs) for C and N were 0.98 and 0.85, with standard errors of prediction (SEPs) of ±0.45 g C kg–1 and ±0.09g Nkg–1, respectively. The generation of δ15N and δ13C models produced different NIR recordings in soils with and without crop residues. Application of discriminant partial least squares (DPLS) statistics to the NIR spectral data allowed us to discriminate soils with and without residues. The prediction confidence for stable isotopes was 90% (internal validation) and 94% (external validation). Modified partial least squares regression was used to estimate δ15N and δ13C. Ratio performance deviation, RSQ, and SEP values obtained for δ13C and δ15N were 2.44 and 3.57, 0.83 and 0.81, ±0.5‰ (parts per thousand) and ±0.45‰ in soils with residues and 2.5 and 3.8, 0.93 and 0.92, and ±0.2‰ and ±0.23‰ in soils without residues, respectively. Overall, results obtained with NIRS were comparable to those obtained using conventional analytical methods, a finding that has wide relevance to agricultural soils and environmental studies in tropical locations. However, further testing is necessary to confirm that the calibration models are neither site nor instrument specific.

- by Mariela Fuentes
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- Plant Biology, Stable Isotopes, Near Infrared, Soil Analysis
- by Daizy Batish
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- Sustainable agriculture, Plant Biology, Molecular Genetics, Cropping Pattern
- by Jagadish Timsina
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- Agronomy, Plant Biology, Crop Residue Burning, Soil sciences
- by Paul Fixen
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- Climate Change, Carbon Dioxide, Global Warming, Environmental Sciences

Purpose of Study: The IoT is an emerging field nowadays and that can be used anywhere in automation, agriculture, controlling as well as monitoring of any object, which exists in the real world. We have to make use of IoT in Agriculture to increase productivity. Agro-industry processes could be more efficient by using IoT. It gives automation to agro-industry by reducing human intervention. In the current scenario, the sometime farmer doesn’t know the current status of the soil moisture and other things related to their land and don’t produce productive results towards crops. The purpose of this research study is to explore the usage of IoT devices and application areas that are being used in agriculture.
Methodology: The methodology behind this study is to identify trends and review the open challenges, application areas and architectures for IoT in agro-industry. This survey is based on a systematic literature review where related research is grouped into four domains such as monitoring, control, prediction, and logistics.
Main Findings: This research study presents a detailed work of the eminent researchers and designs of computer architecture that can be applied in agriculture for smart farming. This research study also highlights various unfolded challenges of IoT in agriculture.
Implications: This study can be beneficial for farmers, researchers, and professionals working in agricultural institutions for smart farming.
Novelty/Originality of the study: Various eminent researchers have been making efforts for smart farming by using IoT concepts in agriculture. But, a bouquet of unfolded challenges is still in a queue for their effective solution. This study makes some efforts to discuss past research and open challenges in IoT based agriculture.

- by Dr. Gulbir Singh and +1
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- Agricultural Engineering, Agricultural Development, The Internet of Things, Web Applications

One of the most important terrestrial pools for carbon (C) storage and exchange with atmospheric CO 2 is soil organic carbon (SOC). Following the advent of large-scale cultivation, this long-term balance was disrupted and increased amounts of SOC were exposed to oxidation and loss as atmospheric CO 2 . The result was a dramatic decrease in SOC. If amounts of C entering the soil exceed that lost to the atmosphere by oxidation, SOC increases. Such an increase can result from practices that include improved: (1) tillage management and cropping systems, (2) management to increase amount of land cover, and (3) ef®cient use of production inputs, e.g. nutrients and water. Among the most important contributors is conservation tillage (i.e., no-till, ridge-till, and mulch-tillage) whereby higher levels of residue cover are maintained than for conventional-tillage. Gains in amount of land area under conservation tillage between 1989 and 1998 are encouraging because of their contributions to soil and water conservation and for their potential to sequester SOC. Other important contributors are crop residue and biomass management and fallow reduction. Collectively, tillage management and cropping systems in the US are estimated to have the potential to sequester 30±105 million metric tons of carbon (MMTC) yr À1 . Two important examples of management strategies whereby land cover is increased include crop rotations with winter cover crops and the conservation reserve program (CRP). Such practices enhance SOC sequestration by increasing the amount and time during which the land is covered by growing plants. Crop rotations, winter cover crops, and the CRP combined have the potential to sequester 14±29 MMTC yr À1 . Biomass production is increased by ef®cient use of production inputs. Optimum fertility levels and water availability in soils can directly affect quantity of crop residues produced for return to the soil and for SOC sequestration. Nutrient inputs and supplemental irrigation are estimated to have the potential to sequester 11±30 MMTC yr À1 . In the future, it is important to acquire an improved understanding of SOC sequestration processes, the ability to make quantitative estimates of rates of SOC sequestration, and technology to enhance these rates in an energy-and input-ef®cient manner. Adoption of improved tillage practices and cropping systems, increased land cover, and ef®cient use of nutrient and water inputs are examples where such information is necessary. Published by Elsevier Science B.V.

- by Rajagopal Vadivel
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- Irrigation, Carbon, Water Availability, Carbon Sequestration

Energy plays a pivotal role in socio-economic development by raising standard of living. It is becoming gradually accepted that current energy systems, networks encompassing every thing from primary energy sources to final energy services, are becoming unsustainable. Development of conventional forms of energy for meeting the growing energy needs of society at a reasonable cost is the responsibility of the Governments. In recent years, public and political sensitivities to environmental issues and energy security have led to the promotion of renewable energy resources. Diversification of fuel sources is imperative to address these issues; and limited fossil resources and environmental problems associated with them have emphasized the need for new sustainable energy supply options that use renewable energies. Development and promotion of new non-conventional, alternate and renewable sources of energy such as solar, wind and bio-energy, etc. are now getting sustained attention. Solar power is one of the hottest areas in energy investment right now, but there is much debate about the future of solar technology and solar energy markets. This investigates the progress and challenges for solar power in Pakistan according to the overall concept of sustainable development, and identifies the region wise potential of solar power in Pakistan and its current status. Barriers are examined over the whole solar energy spectrum and policy issues and institutional roles and responsibilities are discussed.

- by Abdul Waheed Bhutto
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- Engineering, Climate Change, Sustained Attention, Renewable Energy
- by Eric Ranst
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- Carbon Dioxide, Modeling, Ecology, China

SUMMARY - Current pattern of utilisation of non-conventional feed resources (NCFRs) in Africa and Asia and techniques for their efficient use in small ruminant feeding are discussed in this paper. Chronic feed deficits represent a major constraint to animal production in many developing countries. Expanding the feed resource base through utilisation of NCFRs, especially those that do not compete with

- by Harinder Makkar
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- Animal Production, Developing Country, North Africa, Livestock Production

The use of organic matter (OM) has been proposed, for both conventional and biological agriculture systems, to decrease the incidence of plant diseases caused by soilborne pathogens. In this work we review reports on the application of OM amendments, focusing on the suppressive capacity of different OM materials and the response of different soilborne pathogens. A total of 250 articles were analysed, with 2423 experimental case studies. The effect of OM amendments was found to be suppressive in 45% and non-significant in 35% of the cases. In 20% of the cases, a significant increase of disease incidence was observed. Compost was the most suppressive material, with more than 50% of cases showing effective disease control. The effect of crop residues was more variable: it was suppressive in 45% of the cases, but enhanced disease in 28%. Finally, significant disease suppression with peat was recorded only in 4% of the experiments. The ability of OM to suppress disease varied largely with different pathogens: it was observed in more than 50% of the cases for Verticillium, Thielaviopsis, Fusarium and Phytophthora. In contrast, effective control of Rhizoctonia solani was achieved only in 26% of the cases. From this review it emerged that OM amendments have great potential but, at the same time, present some inconsistencies in their application. More investigation on the mechanisms by which OM acts on disease suppression is needed to make the use of these materials more predictable.

- by vincenzo antignani
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- Case Studies, Plant diseases, Case Study, Disease Control

Recent studies revealed that 76.4% of gross energy consumed in Egypt's rural areas originated from building crop residues and dung cakes, while 23.6% of the needs are met by conventional energy sources. The efficiency of releasing energy from biomass by direct burning in traditional primitive stoves is very low (5-10%). Also the organic matter content in the Egyptian agricultural soil is low (about 2%), a level which is considered very poor and needs annual amendment. Besides, the projects for expanding the cultivated area by reclamation of desert sandy soils presents and additional increasing demand for organic manures. The process of biogas generation from crop residues, animal droppings, municipal solid wastes and sewage sludge could positively affect the process of rural development because of the numerous benefits realized from it. Through the cooperation between the Basaisa Community Development Association (Basaisa-IRTECTAP), the Agricultural Research Center (ARC) and the Technology Transfer Component of the National Agricultural Research Project (NARP-TTC) it was possible to plan and implement a realistic promotional program to assist the process of transfer the biogas technology to the villages of Egypt. Over 5000 rural people were reached during the promotion campaign, 40 persons got practical training on the technology, and 18 family size units and 2 farm size units were built to-date. The paper discusses the factors affecting the biogas technology transfer program and reports on the field experience with emphasis on how the problems of promoting biogas at the village level are dealt with. Guidelines for successful transfer of the technology to rural areas are given.

- by Salah Arafa
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- Community Development, Rural Development, Technology transfer, Municipal Solid Waste

The importance of reduced tillage in sustainable agriculture is well recognized. Reduced-tillage practices (which may or may not involve retention of crop residues) and their effects differ from those of conventional tillage in several ways: soil physical properties; shifts in host-weed competition; soil moisture availability (especially when sowing deeply or under stubble); and the emergence of pathogen populations that survive on crop residues. There may be a need for genotypes suited to special forms of mechanization (e.g. direct seeding into residues) and to agronomic conditions such as allelopathy, as well as specific issues relating to problem soils. This article examines issues and breeding targets for researchers who seek to improve crops for reduced-tillage systems. Most of the examples used pertain to wheat, but we also refer to other crops. Our primary claim is that new breeding initiatives are needed to introgress favourable traits into wheat and other crops in areas where reduced or zero-tillage is being adopted. Key traits include faster emergence, faster decomposition, and the ability to germinate when deep seeded (so that crops compete with weeds and use available moisture more efficiently). Enhancement of resistance to new pathogens and insect pests surviving on crop residues must also be given attention. In addition to focusing on new traits, breeders need to assess germplasm and breeding populations under reduced tillage. Farmer participatory approaches can also enhance the effectiveness of cultivar development and selection in environments where farmers' links with technology providers are weak. Finally, modern breeding tools may also play a substantial role in future efforts to develop adapted crop genotypes for reduced tillage.

- by Ramesh Chand
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- Technology, Sustainable agriculture, South Asia, Biological Sciences

Banana is the most important food crop in Uganda. However, there has been a decline in productivity, attributed to declining soil fertility, drought, pests and diseases and crop management factors. This study aimed to explore the possibility of increasing yields through the use of fertilizer and mulch, and to evaluate the benefits of these inputs across the major banana producing regions in Uganda. This study was carried out in 179 smallholder plots in Central, South, Southwest and East Uganda in 2006/7. Half of the plots were ‘demonstration plots’ of an agricultural development project, while the other half were neighboring farmer plots that acted as ‘control’. Demonstration plots received mineral fertilizer (100% of plots), averaging 71 N, 8 P, 32 K kg ha−1 yr−1 and external mulch from grass and crop residues (64% of plots), whereas control plots received no mineral fertilizer and little external mulch (26% of plots). Demonstration plots had significantly (P ⩽ 0.05) higher yields than control plot in Central, South and Southwest, but average yield increases varied from 4.8 t ha−1 yr−1 (Southwest) to 8.0 (Central), and 10.0 (South). Average weevil corm damage (3%) and nematode-induced root necrosis (7%) was low and similar for both plot types, so yield increases could only be explained by the use of fertilizer and mulch. The highest demonstration plot yield increases were observed where fertilizer addressed key nutrient deficiencies identified using the compositional nutrient diagnosis approach. Farm gate bunch prices declined from 0.17 (Central Uganda) to 0.07 USD kg−1 (Southwest Uganda). Consequently, average marginal rate of return (MRR) of fertilizer and mulch use ranged from 0.1 (Southwest) to 5.8 (Central). The technologies were likely to be acceptable to farmers (MRR ⩾ 1.00) up to 160 km away from the capital. Fertilizer use is likely to be acceptable in all regions (MRR = 0.7–9.4) if local fertilizer prices of 2006/7 (average USD 0.56 kg−1 of fertilizer) declined by 50%. Doubling of fertilizer prices is likely to make fertilizer use unacceptable beyond 100 km away from the capital. The study concludes that there is scope for increased input use in banana systems in Uganda, but that regional variations in crop response, input/output prices, and price fluctuations have to be taken into account.► Modest fertilizer and mulch applications increase highland banana yields by 4.8 to 10.0 t ha−1 yr−1. ► Yield increases were highest where fertilizer applied addressed key nutrient deficiencies. ► Farm gate banana prices declined by >50% when moving from the Kampala urban market to >300 km distance. ► Application of external nutrient inputs can be safely recommended close (<100 km) to Kampala market but depending on input-output price developments may not be profitable in the main banana production areas in Southwest Uganda.

- by Piet van Asten
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- Agricultural Development, Environmental Sciences, Rate of return, Profitability

Agricultural crop residues (palm oil empty fruit bunches-EFB) were used as raw material for cellulose, lignin and hemicelluloses obtaining following sustainable criteria. An organosolv pulping process based on ethylene glycol-water mixtures, which allowed an easy recycling of solvents as well as the recovery of generated by-products, was used to induce delignification. Computer simulations using commercial software (Aspen Plus) were made on the whole process in order to design the solvents recovery stages and optimise the operation conditions. Laboratory experiments were carried out with the aim of characterizing raw material, black liquors and released by-products. Considerable high proportion of recycled solvents (91 wt% ethylene glycol and 88 wt% water) was reached with the proposed scheme. This resulted in 70 and 80 wt% reduction of fresh solvent input for ethylene glycol and water respectively, thus reducing the environmental impact of the process. EFB organosolv pulp could be considered an acceptable alternative for producing certain paper qualities with moderate strength requirements while allowing an agricultural residue from a major economic activity (viz. oil palm production) to be exploited.

- by A. Tejado and +1
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- Chemical Engineering, Computer Simulation, Raw materials, Process Simulation

1] A 3-year field experiment was conducted to simultaneously measure methane (CH 4 ) and nitrous oxide (N 2 O) emissions from rice paddies under various agricultural managements including water regime, crop residue incorporation, and synthetic fertilizer application. In contrast with continuous flooding, midseason drainage incurred a drop in CH 4 fluxes while triggering substantial N 2 O emission. Moreover, N 2 O emissions after midseason drainage depended strongly on whether or not fields were waterlogged due to intermittent irrigation. Urea application tended to reduce CH 4 emissions but significantly increased N 2 O emissions. Under a water regime of flooding-midseason drainagereflooding-moist intermittent irrigation but without water logging (F-D-F-M), both wheat straw and rapeseed cake incorporation increased CH 4 emissions by 252%, and rapeseed cake increased N 2 O by 17% while wheat straw reduced N 2 O by 19% compared to controls. Seasonal average fluxes of CH 4 ranged from 25.4 mg m À2 d À1 when no additional residue was applied under the water regime of flooding-midseason drainagereflooding to 116.9 mg m À2 d À1 when wheat straw was applied at 2.25 t ha À1 under continuous irrigation flooding. Seasonal average fluxes of N 2 O varied between 0.03 mg N 2 O-N m À2 d À1 under continuous flooding and 5.23 mg N 2 O-N m À2 d À1 under the water regime of F-D-F-M. Both crop residue-induced CH 4 , ranging from 9 to 15% of the incorporated residue C, and N 2 O, ranging from 0.01 to 1.78% of the applied N, were dependent on water regime in rice paddies. Estimations of net global warming potentials (GWPs) indicate that water management by flooding with midseason drainage and frequent water logging without the use of organic amendments is an effective option for mitigating the combined climatic impacts from CH 4 and N 2 O in paddy rice production. (2005), A 3-year field measurement of methane and nitrous oxide emissions from rice paddies in China: Effects of water regime, crop residue, and fertilizer application, Global Biogeochem. Cycles, 19, GB2021,

- by Yao Huang
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- Geochemistry, Water Management, Global change, Seasonality

Soil tillage practices can affect soil hydraulic properties and processes dynamically in space and time with consequent and coupled effects on chemical movement and plant growth. This literature review addresses the quantitative effects of soil tillage and associated management (e.g., crop residues) on the temporal and spatial variability of soil hydraulic properties. Our review includes incidental management effects, such as soil compaction, and natural sources of variability, such as topography. Despite limited research on space-time predictions, many studies have addressed management effects on soil hydraulic properties and processes relevant to improved understanding of the sources of variability and their interactions in space and time. Whether examined explicitly or implicitly, the literature includes studies of interactions between treatments, such as tillage and residue management. No-tillage (NT) treatments have been compared with various tillage practices under a range of conditions with mixed results. The trend, if any, is for NT to increase macropore connectivity while generating inconsistent responses in total porosity and soil bulk density compared with conventional tillage practices. This corresponds to a general increase in ponded or near-zero tension infiltration rates and saturated hydraulic conductivities. Similarly, controlled equipment traffic may have significant effects on soil compaction and related hydraulic properties on some soils, but on others, landscape and temporal variability overwhelm wheel-track effects. Spatial and temporal variability often overshadows specific management effects, and several authors have recognized this in their analyses and interpretations. Differences in temporal variability depend on spatial locations between rows, within fields at different landscape positions, and between sites with different climates and dominant soil types. Most tillage practices have pronounced effects on soil hydraulic properties immediately following tillage application, but these effects can diminish rapidly. Long-term effects on the order of a decade or more can appear less pronounced and are sometimes impossible to distinguish from natural and unaccounted management-induced variability. New standards for experimental classification are essential for isolating and subsequently generalizing space-time responses. Accordingly, enhanced methods of field measurement and data collection combined with explicit spatio-temporal modeling and parameter estimation should provide quantitative predictions of soil hydraulic behavior due to tillage and related agricultural management. Published by Elsevier B.V.

Addis Ababa, with an estimated human population of over 3 million, has a high demand for cereals, pulses, fresh vegetables, fruits, milk and milk products and meat and eggs. The Ada'a Woreda is one of the important areas that supply the well known 'maja' teff, chickpeas, fresh vegetables, eggs and chicken, meat and milk. The Woreda capital, Debre Zeit town, is only 45 km southeast of Addis Ababa and has a very good road and railway connection. The Ada'a Dairy Cooperative was established in 1998 in Debre Zeit based on its comparative market advantage, the conducive agro-ecological conditions for dairy production and the available support services. The cooperative was established with 34 members and an initial capital of 3,400 Birr. The main objectives are to minimize transaction costs, reduce price fluctuations over seasons, increase production efficiency, improve incomes and create job opportunities. Milk collection and marketing started in January 2000, with a daily total of 308 liters. The association has made significant progress so far and currently has over 850 members (about 50% female) who individually own over 3000 dairy cows. The current capital of the association has increased to USD 138,029. The number of milk collection sites has increased to 10 and job opportunity has been created for 62 staff. Daily milk collection has increased to over 8,000 liters and is mainly sold to the Dairy Development Enterprise (DDE) in Addis Ababa. The cooperative has established a small processing unit for the production of butter, yoghurt and cottage cheese during periods of excess supply. Members use mainly crossbred animals and the management level is relatively intensive with limited land area. Most animals are stall fed. The cooperative supplies inputs such as grass hay, concentrate feeds, veterinary drugs and services, and artificial insemination service to members at reasonable prices. Rural dairy farmers are joining the cooperative, taking advantage of market access for their milk. Inputs required in dairy production include feeds and water, labour, veterinary drugs and services, artificial insemination and equipment and utensils. The largest input in terms of volume and financial requirements is feed. These involve roughages and concentrate feeds. The main rural areas that provide roughage feeds (grass hay and crop residues) include Selale, Ada'a and adjacent Woredas, and Arsi. Concentrate feeds such as bran, middlings, oil seed cakes, molasses are supplied by ago-industries around Addis Ababa, Debre Zeit and Nazareth, but the row materials come from various parts of the country. Molasses is supplied from Wonji and Shoa Sugar Estates. Another major input is water which is used for animal consumption, washing and cleaning purposes. Most dairy farmers use expensive municipal water supply. Most of the milk collected is supplied to DDE. Pasteurized and processed products are mainly sold in Addis. Some fresh milk is also sold directly to hotels and restaurants in Addis Ababa, Debre Zeit, Dukem and Nazareth towns. In addition, milk collected from Ada'a by the Sebeta agro-industry is processed and supplied to urban centres as far as Bahir Dar. Manure produced from dairy farms is also supplied to a limited extent to rural areas, particularly to horticultural crops producing farms. A strong and organized rural-urban linkage is evolving informally at the moment and this should be recognized and strengthened to benefit both rural and urban dwellers in taking advantage of the value chain. Although urban and peri-urban dairy production system plays important role in the national economy, the system has been marginalized and there is limited research and institutional support addressing this issue. This paper presents the activities and achievements of the Ada'a dairy cooperative and also highlights the rural and urban linkages through the value chain of milk production, processing and marketing.

- by Nigatu Alemayehu
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- Market Orientation, Value Chain, Seasonality, Water Supply

A farm survey was carried out in 155 Ghanaian villages covering parts of the forest and savanna zones of West Africa to assess farmers' views on 'soil organic matter' (SOM) and its management. The results of a closed questionnaire accompanied by open discussions showed that most farmers are well aware of SOM and its importance for crop yields. In southern Ghana, farmers perceive SOM generally by its colour, while in northern Ghana, it is mostly assessed by the density and kind of vegetation. Farmers' perception of the properties of SOM was directed at its main functions as a primary provider of plant nutrients and its ability to conserve water. Other properties mentioned were the improvement of soil aeration and drainage, the loosening of soil structure as well as its impact on soil temperature. The major strategies farmers used in maintaining or augmenting SOM levels were: manure application, mulching with crop residues, slashing weeds without burning, composting, and shifting cultivation (natural fallow). Promoted technologies, such as green manuring, no tillage, or agroforestry were used only by a few of the farmers interviewed. The differences between farmers' views and strategies in the two zones as well as farmers' constraints in SOM management are discussed. It appears that the level of farmers' commitment to excellent soil management can vary with biophysical as well as socio-economic conditions.

- by Charles Quansah and +1
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- Analytical Chemistry, West Africa, IT Management, Indigenous Knowledge

Soil fertility depletion has been described as the single most important constraint to food security in West Africa. Over half of the African population is rural and directly dependent on locally grown crops. Further, 28% of the population is chronically hungry and over half of people are living on less than US$ 1 per day as a result of soil fertility depletion.

- by Joseph Kimetu
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- West Africa, Food Security, Environmental Sciences, Agricultural Systems

Soil organic carbon C modeling C sequestration Organic residue Crop residue Tillage a b s t r a c t

- by Ronald Follett and +2
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- Multidisciplinary, Ecological Modelling, Pacific Northwest, Regression Analysis
- by Rajagopal Vadivel
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- Earth Sciences, Soil, Carbon, Biological Sciences

Around 50% of people, almost all in developing countries, rely on coal and biomass in the form of wood, dung and crop residues for domestic energy. These materials are typically burnt in simple stoves with very incomplete combustion.... more

- by kusum subedi
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- Poverty, Developing Countries, Air pollution, Public Health

Globally, almost three billion people rely on biomass (wood, charcoal, crop residues, and dung) and coal as their primary source of domestic energy. Exposure to indoor air pollution from the combustion of solid fuels has been implicated, with varying degrees of evidence, as a causal agent of of disease and mortality in developing countries. We review the current knowledge on the relationship between indoor air pollution and disease, and on the assessment of interventions for reducing exposure and disease. Our review takes an environmental health perspective and considers the details of both exposure and health effects that are needed for successful intervention strategies. We also identify knowledge gaps and detailed research questions that are essential for successful design and dissemination of preventive measures and policies. In addition to specific research recommendations, we conclude that given the central role of housing, household energy, and day-to-day household activities in determining exposure to indoor smoke, research and development of effective interventions can benefit tremendously from integration of methods and analysis tools from a range of disciplines-from quantitative environmental science and engineering, to toxicology and epidemiology, to the social sciences.

- by Daniel Kammen
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- Environmental Science, Biomass, Environmental Health, Developing Countries

- by Giuliano Bonanomi
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- Case Study, Disease Control, Crop Residue Burning, Plant Disease

One of the options to ameliorate the deleterious effects of sodic water irrigation is to apply gypsum to soil. We examined whether the application of organic manures or crop residue can reduce the need for gypsum in calcareous soils. A long-term field experiment with annual rice-wheat cropping rotation was conducted for 15 years (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) on a non-saline calcareous sandy loam soil (Typic Ustochrept) in northwestern, India. The irrigation water treatments included good quality canal water (CW) and sodic water (SW) with residual sodium carbonate (RSC) of 10 mmol c L −1 from 1991 to 1999 and of 12.5 mmol c L −1 from 2000 onwards. Gypsum was applied at 0, 12.5, 25, and 50% of the gypsum requirement (GR), to neutralize RSC of the SW. Three organic material treatments consisted of application of farmyard manure (FYM) at 20 Mg ha −1 , Sesbania green manure (GM) at 20 Mg ha −1 , and wheat straw (WS) at 6 Mg ha −1 . The organic materials were applied every year to the rice crop. Continuous irrigation with sodic water for 15 years without gypsum or organic materials resulted in a gradual increase in soil pH and exchangeable sodium percentage (ESP), deterioration of soil physical properties, and decrease in yields of both rice and wheat. The cumulative yield loss in SW irrigated plots without gypsum and organic materials remained <1.5 Mg ha −1 for up to eight years in the case of rice and up to nine years in the case of wheat. Thereafter, marked increase in pH and ESP resulted in further depression in yields of rice by 1.6 Mg ha −1 year −1 and wheat by 1.2 Mg ha −1 year −1 . Application of gypsum improved physical and chemical properties of the soil. The beneficial effects on crop yields were visible up to 12.5% GR in rice and up to 50% GR in wheat in most of the years. All the organic materials proved effective in mobilizing Ca 2+ from inherent and precipitated CaCO 3 resulting in decline in soil pH and ESP, increase in infiltration rate, and a increase in the yields of rice and wheat crops. Although the application of organic materials resulted in comparable reductions in pH and ESP, the increase in yield with SW was higher for both crops with FYM. Pooled over the last six years (2000)(2001)(2002)(2003)(2004)(2005)(2006), application of FYM resulted in 38 and 26% increase in rice and wheat yields, respectively, over SW treatment; corresponding increases in 50% GR treatment (recommended level) was 18 and 19%. During these years, application of GM and WS increased wheat yields by 20%; for rice, GM resulted in 22% increase compared to 17% in WS amended SW irrigated plots. Combined application of gypsum and organic materials did not increase the yields further particularly in the case of FYM and GM treated plots. This long-term study proves that organic materials alone can be used to solubilize Ca from inherent and precipitated CaCO 3 in calcareous soils for achieving sustainable yields in sodic water irrigated rice-wheat grown in annual rotation. The results can help reduce the dependency on gypsum in sodic water irrigated calcareous soils.

- by Nguyen Thuy
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- Field Crops, Crop Residue Burning, Irrigation Water, Soil sciences

Wheat and barley straws, corn stover and switchgrass at two moisture contents were ground using a hammer mill with three different screen sizes (3.2, 1.6 and ). Energy required for grinding these materials was measured. Among the four materials, switchgrass had the highest specific energy consumption (), and corn stover had the least specific energy consumption () at screen size. Physical properties of grinds such as moisture content, geometric mean diameter of grind particles, particle size distribution, and bulk and particle densities were determined. Second- or third-order polynomial models were developed relating bulk and particle densities of grinds to geometric mean diameter within the range of 0.18–. Switchgrass had the highest calorific value and the lowest ash content among the biomass species tested.

- by Lope Tabil
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- Engineering, Materials Science, Biomass, Density

Low inherent soil fertility in the highly weathered and leached soils largely accounts for low and unsustained crop yields in most African countries. But in particular, the major nutrients, nitrogen (N) and phosphorus (P), are commonly deficient in these soils. This scenario of nutrient depletion is reflected in food deficits and hence the food aid received continuously, specifically in sub-Saharan Africa. Undoubtedly, substantial efforts have been made in the continent to replenish the fertility of degraded soils in attempts to raise crop yields, towards self-sufficiency and export. Such efforts consist of applications of both organic and inorganic resources to improve the nutrient status of soils and enhanced nutrient uptake by crops, provided that soil moisture is adequate. Overall, positive crop responses to these materials have been obtained. Thus in the East African region, maize (staple) yields have been raised in one growing season from below 0.5 t/ha without nutrient inputs, to 3-5 t/ha from various nutrient amendments at the smallhold farm level. However, in spite of the positive crop responses to nutrient inputs, farmers are generally slow to adopt the soil fertility management technologies. In this paper we review the impact of some technologies, focussing the use of nutrient resources of different characteristics (qualities) in relation to improved crop yields, with an overall goal to enhance technology adoption. Thus, inorganic resources or fertilizers often give immediate crop responses, but their use or adoption is rather restricted to large-scale farmers who can afford to buy these materials. Organic resources, which include crop residues, water hyacinth and agroforestry shrubs and trees, are widely distributed, but they are generally of low quality, reflecting the need to apply large quantities to meet crop nutrient demands. Moreover, most organics will add N mainly to soils. On the other hand, phosphate rocks of varying reactivity are found widely in Africa and are refined elsewhere to supply soluble P sources. The recently developed soil fertility management options in East Africa have targeted the efficient use of N and P by crops and the integrated nutrient management approach. Some people have also felt that the repackaging of inputs in small, affordable quantities, such as the PREP-PAC described in this paper, may be an avenue to attract smallhold farmers to use nutrient inputs. Nonetheless, crop responses to nutrient inputs vary widely within and across agroecozones (AEZs), suggesting specificity in recommendations. We highlight this observation in a case study whereby eight soil fertility management options, developed independently, are being tested side-by-side at on-farm level. Farmers will be empowered to identify technologies from their own choices that are agronomically effective and economically friendly. This approach of technology testing and subsequent adoption is recommended for technology development in future.

- by R. Muasya and +2
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- Analytical Chemistry, Food Aid, East Africa, Technology development

In an experiment conducted over 8 years at the research farm of the National Research Centre for Weed Sciences, Jabalpur, we investigated the effects of mineral fertilizer and organic manures on K balances and non-exchangeable K release kinetics in a Typic Haplustert under a rain-fed rice (Oryza sativa L.) and irrigated wheat (Triticum vulgare L.) system. Each year, rice was grown with variable levels of fertilizer N with and without organic manures, while recommended rates of 26 kg P ha À1 and 33 kg K ha À1 were applied to both the crops. Wheat was grown without organic manure but with the same levels of fertilizer N as for rice. The apparent K balance was measured as the difference between total K added and that removed by the crop. Increasing levels of fertilizer N resulted in an increase in the negative K balance from 56 kg ha À1 yr À1 (control) to 103 kg ha À1 yr À1 at 90 kg N ha À1 and 156 kg ha À1 at 180 kg N ha À1 . Incorporation of farmyard manure (FYM) or green manure (GM) with fertilizer N reduced the negative K balance. Repeated extraction of soil with 0.01 M CaCl 2 revealed that continuous cropping for 8 years either without fertilizer N (control) or with 90 kg N ha À1 reduced the cumulative K release. However, the application of 180 kg ha À1 of fertilizer N not only maintained the cumulative K release but also improved it. Incorporation of 5 t FYM or 6 t GM ha À1 with 90 kg N ha À1 resulted in an increase in K release by 58 and 37 mg kg À1 soil, respectively, over the values measured in a soil sample collected at the onset of the experiment. A parabolic diffusion equation described the release rate of the non-exchangeable K. The equation suggested that the application of fertilizer N reduced the release rate of K, whereas the incorporation of manure, with fertilizers, increased it over the values obtained from soil collected at the onset of the experiment. The large cumulative K release at 180 kg N ha À1 was due to the amount of K released initially. Continuous cropping at a fertilizer level of 33 kg K ha À1 may pose a threat to the sustainability of the rice-wheat system. Recycling of crop residue or application of higher levels of fertilizer K may provide long-term sustainability to the system. #

- by Dipen Ch. Nath
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- Kinetics, Field Crops, Potassium, Crop Residue Burning