Muhammad Shaukat - Academia.edu (original) (raw)

Papers by Muhammad Shaukat

Biogeochemical models estimate soil organic carbon (SOC) sequestration, crop growth, and yield. T... more Biogeochemical models estimate soil organic carbon (SOC) sequestration, crop growth, and yield. The DeNitrification and DeComposition (DNDC) model was used to simulate soil SOC dynamics and harvested C-biomass in rice-wheat rotation under organic/inorganic fertilizations with conventional tillage (CT) and reduced tillage (RT). Before calibration, DNDC under-predicted harvestable grain C-biomass of rice by 29.22% to 42.14% and over-simulated grain C-biomass of wheat by 55.01% with equal amounts of NPK and animal manure applied under CT. However, after calibration by adjusting default values of soil/crop parameters, DNDC simulated harvestable grain C-biomass of both crops very close to observed values (only -2.81% to -6.17% less). DNDC also predicted effects of nutrient management practices on grain C-biomass of rice/wheat under CT/RT using d-index (0.76 to 0.96) and the calculated root mean squared error (RMSE of 165.36 to 494.18 kg C ha-1). DNDC simulated SOC trends for rice-wheat u...

Sustainability

Rice–wheat crop rotations have high carbon fluxes. A 2-year field study in Punjab, Pakistan quant... more Rice–wheat crop rotations have high carbon fluxes. A 2-year field study in Punjab, Pakistan quantified impacts of different nutrient management on harvestable carbon biomass, crop-derived C, soil organic C sequestration (SCS), and decomposition. Treatments included different combinations of mineral fertilizer, animal manure (20 Mg ha−1), and incorporated crop residue in a split-plot design under conventional tillage (CT) and reduced tillage (RT). Combined use of mineral fertilizer and manure resulted in (1) 12.56% to 53.31% more harvestable C biomass compared to use of fertilizer and manure alone and (2) 18.27% to 60.72% more crop-derived C inputs relative to using only fertilizer or manure across both tillage practices. Combined fertilizer/manure treatments also significantly enhanced SCS relative to using fertilizer alone. Using only manure increased SCS by 63.25% compared with fertilizer alone across both tillage practices. The relationship between SCS and C inputs indicated high...

Journal of Applied Research in Plant Sciences

To enhance crop yields, nitrogen is one of essential basic nutritional elements that enable any p... more To enhance crop yields, nitrogen is one of essential basic nutritional elements that enable any plant to withstand in stressful conditions. An experiment was carried out to investigate the impact of N rates and its application timings on growth, development and sugarcane yield at farm area of Sugarcane Research Institute, Faisalabad, Pakistan for two consecutive crop seasons (spring 2014 and 2015). Four Nitrogen (N) rates viz.170, 227, 284 and 341 kg ha-1were applied at four different application schedules i.e. T1= 45-75-90 days after planting (DAP); T2= 45-75-90-120 DAP;T3= 45-75-90-120-150 DAP and T4= 45-75-90-120-150-180 DAP, in RCBD having three replications. The results revealed that the treatments significantly affected quantitative traits like tillers plant-1, cane girth, millable count, cane and sugar yield and growth parameters like leaf area index (LAI), leaf area duration (LAD), seasonal total dry matter accumulation (TDM) and seasonal crop growth rate (CGR). Interactive ...

Ecological Modelling, 2022

Rice-wheat cropping sequence (RWS) is one of the predominant cropping systems, occupying in almos... more Rice-wheat cropping sequence (RWS) is one of the predominant cropping systems, occupying in almost 26.7 M ha in various Asian countries. Indo-Gangetic Plains (IGP) of South Asia contributes about 13.0 M ha in the total area of RWS (Timsina and Connor, 2001). Among South Asian countries, this system is occupied on 12.5 M ha in India (10 M ha is that of the IGP), 2.3 M ha in Pakistan, 0.8 M ha in Bangladesh and 0.5 M ha in Nepal (Timsina and Connor, 2001). Keeping in view the importance of RWS, the productivity of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) must be enhanced either through the best farm management practices, including nutrient, irrigation and weed management etc. or via genetic modification. In this scenario, the phenological events of both crops can play a significant role to harvest the maximum yields in RWS. Therefore, growth and developmental events as well as partitioning of photoassimilates are mainly determined by the crop phenology (Rehman et al., 2...

International Journal of Plant Production, 2021

Archives of Agronomy and Soil Science, 2020

Quantifying soil organic carbon (SOC) dynamics is critical for monitoring agricultural sustainabi... more Quantifying soil organic carbon (SOC) dynamics is critical for monitoring agricultural sustainability and mitigating global climate change. A study was done to investigate the SOC changes between 2003 and 2016 by DeNitrification-DeComposition model in an intensively cultivated region of eastern China, using a detailed high-resolution soil database, which contained 4875 sites (0-20 cm depth) with the sampling density of one sample per km 2 in 2003. Results showed good performance for simulating the SOC dynamics in the study area. Spatial analysis showed that 71% of the study area gained C whilst 29% maintained their C balance with no C loss in all areas. Results suggest that the current management practice facilitates soil C sequestration in this region although soil type also plays an important role. SOC density (SOCD) in lime concretion black soil was significantly higher than those in other soils. The averaged global warming potential ranged from 3865.8 to 7110.8 kg CO 2 equivalent ha-1 yr-1 from 2003 to 2016 with CH 4 contributing the largest proportion, which may be associated with the high input of fertilizer. Spatially high resolution estimates of SOC using DNDC can support dual agricultural and carbon management in this region.

Journal of Plant Nutrition and Soil Science, 2017

Crop productivity in future may be limited due to water scarcity. However, foliar spray of plant ... more Crop productivity in future may be limited due to water scarcity. However, foliar spray of plant growth promoters may boost crop production even in adverse environments. In the present study, foliar application of one natural (moringa leaf extract, 3% MLE) and four synthetic (Polydol, Multisol, Classic, and Asahi Star) were applied at tillering, jointing, booting, and heading growth stages of wheat (Triticum aestivum L.) during severe, moderate, and light drought and wellwatered condition. No spray and water spray were taken as controls. Results showed significant reduction in growth parameters such as total dry matter production, mean crop growth rate, net assimilation rate, leaf area index, and duration due to drought employed at various phenophases of wheat. However, improvement in these parameters was observed after foliar application of growth promoters, whereas interactive effects between factors were found non-significant. The activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were more accelerated under drought treatments from exogenously supplied growth promoters. Foliar application of promoters significantly alleviated drought-induced reduction of yield and related traits. Grain weight (15%) and grain yield (27%) were improved due to exogenously applied MLE under moderate drought stress treatments relative to controls. Furthermore, 16% higher grain yield and 17% saving of irrigation water over fully irrigated and without promoter treatment (farmers' practice) was recorded from foliar-applied MLE under skipped irrigation at jointing. In conclusion, foliar-applied MLE may ameliorate drought-induced deleterious effects by enhancing antioxidant activities under drought stress.

Climate Change and Agriculture, 2019

Salinity stress is one of the most vital abiotic stresses which results in significant damages of... more Salinity stress is one of the most vital abiotic stresses which results in significant damages of agricultural production, particularly in arid and semi-arid areas of the world. Salinity causes by high accumulation of soluble salt, especially NaCl in soil and water. Salinity hampers the growth and survival of many field crops such as rice, wheat, maize, cotton, sugarcane, and sorghum. It affects the plant growth by three ways such as osmotic stress linked with an increase of phytotoxic ions, ionic stress e in the cytosol, and oxidative stress facilitated by reactive oxygen species (ROS). These stresses caused by salinity hinder the water uptake, causes ion imbalance, ROS production, and hormonal imbalance, and results in the decline of photosynthesis activities reduce the plant growth and final yield. However, the sensitivity of field crops depends on the nature of cultivar and growth stages. There are many strategies to cope with salinity stress which are the development of salinity tolerant crop cultivators by using genetic and molecular techniques such as QTLs and CRISPR CAS9 technique, nutrients management strategies, use of hormones regulators (AVG, 1-MCP, D-31). This chapter will give a brief idea to the scientist to understand the effects of salinity on field crops and their management strategies.

Journal of Environmental Management, 2019

Synthetic fertilizers are major agents of gaseous emissions including nitrous oxide (N 2 O), and ... more Synthetic fertilizers are major agents of gaseous emissions including nitrous oxide (N 2 O), and rice cultivation is a primary source of methane (CH 4) emission. Biochar (BC) addition to agricultural soils is a potential approach to mitigate N 2 O and CH 4 emissions. This greenhouse study was conducted to assess the simultaneous effects of BC and nitrogen (N) fertilization to reduce N 2 O and CH 4 emissions along with higher biomass accumulation in rice under controlled conditions. Nine treatment combinations of BC amendments at 0, 2 and 4% by weight (weight of BC/weight of soil) mixed into 3500 g of unsterile soil with 0, 70 and 140 kg N ha −1 were used in growing rice. Results show that BC-only treatments enhanced the volumetric water contents (VWC) by 9-14% and soil pH by 5-7% coupled with higher daily and cumulative seasonal CH 4-C fluxes by 85-95% and 48-51%, respectively, compared with control treatment. Under 2% and 4% BC amendments, N at 140 kg ha −1 lowered the daily and cumulative seasonal CH 4-C fluxes by 24-42% and 20-30%, respectively as compared to 70 kg N ha −1. Furthermore, BC amendments in N-treated soils reduced the daily and total seasonal N 2 ON emissions by 27-67% and 49-61%, respectively, relative to N-only treatments. However, N addition in BC-amended soils showed 10-16% decreased VWC compared with the BC-only treated soils. In terms of rice growth, BC-only reduced the above-and below-ground biomass accumulation, delayed the tillering phase, and resulted in fewer vegetative tillers except for BC-treated pots with 140 kg N ha −1. Thus, this study suggests that the use of BC amendment at 2% with 140 kg N ha −1 may be a beneficial strategy to reduce the net GHG emissions from paddy rice in an Alfisol.

Scientia Horticulturae, 2019

Soil salinity is hampering the final output of crops by disturbing a set of physiological process... more Soil salinity is hampering the final output of crops by disturbing a set of physiological processes. The current study assessed; how did salt acclimation improve the salinity tolerance in field pea. Firstly, the 2-day old seedlings of pea (P. sativum) were grown in 105:15:117 ppm NPK solution for five days. Initially, two groups of seedlings were selected: acclimated (seedlings were exposed to 15 and 25 mM NaCl solution along with NPK solution for one week) and not acclimated. Further, the seedlings from both groups were grown in 4-kg plastic pots against moderate and severe salinity i.e. salinity levels of 6 and 9 dS m −1 for moderate and severe salt stress, respectively. Part of plants originated from the not acclimated group was kept in pots without salt stress as referent control. Different physiological kinetics were studied from control, acclimated and non-acclimated plants. Results show no detrimental effects of the salt acclimation on plant growth. Therefore, 15 mM NaCl acclimation and control treatments produced the plants with similar above-ground biomass. Further, acclimation triggered the accumulation of Na + ions and prevention of K + ions leakage primary from the root tissues, leading to higher photosynthetic rate (Pn), stomatal conductance (Gs) and chlorophyll contents. Subsequently, the acclimated plants either by 15 mM or 25 mM mediated relatively higher K + ions in roots along with low sequestration of Na + ions under moderate and severe salinity, suggesting that short-term exposure to salinity activates an array of physiological kinetics which enabling the plants to withstand severe salinity conditions. In conclusion, Acclimation with 15 mM NaCl solution was most effective to stimulate K + sequestration in both leaves and roots, leading to i) higher photosynthetic rate and stomatal conductance, ii) more Chl a and total chlorophyll scores, and iii) high relative water contents and more dry biomass accumulation.

Geocarto International, 2019

We demonstrated an innovative learning method of convolutional neural network (CNN) to identify l... more We demonstrated an innovative learning method of convolutional neural network (CNN) to identify landuse and land cover (LULC) patterns and extract features to disaggregate socioeconomic factors by using remote sensing imageries at 30 m spatial resolution. The training labels were extracted from the historical LULC map to reduce the huge cost of labelling work, and to provide an inaccuracy but sufficient training dataset. The fully connected layer of the trained CNN was extracted as disaggregating features to map socioeconomic factors of population and gross domestic product (GDP). Results indicate that current method can attain 92% overall agreement of LULC identification with the cross-validation of other products. The determination coefficient of disaggregating socioeconomic factors can reach 0.945 for population density, and 0.876 for GDP density with the cross-validation at county level.