Improvement of soil aggregate stability by repeated applications of organic amendments to a cultivated silty loam soil (original) (raw)
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EFFECT OF ORGANIC AMENDMENTS ON SOIL AGGREGATE STABILITY
Intensive agriculture is known to cause a decline in soil organic matter content and alter soil structure. The objective of this study was to compare the effect of two urban composts (a municipal solid waste com- post, MSW and a biowaste compost, BW) and a farmyard manure (FYM) on aggregate stability in a loamy soil under field condition. Laboratory incubations of calibrated aggregates added of the same organic amendments were realized in controlled conditions (28 and 4 °C) to confirm the effects observed in field conditions. After one application of the MSW and BW composts in the field experiment, aggregate stabi- lity increased compared to the control plot. In lab conditions, MSW and FYM enhanced the aggregate sta- bility, more at 4°C than at 28°C. In both experiments, the aggregate stability were related to the stimula- tion of microbial activity after addition of still highly biodegradable organic amendments, more persistent at 4°C than at 28°C.
Soil Aggregate Stability Improvement with Urban Composts of Different Maturities
Soil Science Society of America Journal
Organic matter controls aggregate stability in loam soils. Intensive farming can lead to a decrease in soil organic matter content. In areas where livestock have disappeared, the recycling of composted urban organic wastes on agricultural soils may represent a valuable source of organic matter fir restoring soil organic matter content. The effects on the aggregate stability of a silt loam soil of three urban composts (a municipal solid waste compost, a co-compost of sewage sludge and green waste, and a biowaste compost) sampled at two different stages of maturity (immature and mature composts) were studied during laboratory incubations. The results were related to (i) compost organic matter biodegradability, biochemical fractions, and humic substance content, (ii) microbial activity evaluated through organic C mineralization and microbial and fungal biomass evolution, (iii) hot-water-extractable polysaccharides, and (iv) aggregate hydrophobicity as revealed by the water drop penetra...
Soil Research, 2014
Recycling of organic wastes via their incorporation in cultivated lands is known to alter soil structural stability. Aggregate stability tests are commonly used to express quantitatively the susceptibility of soil structural stability to deformation. The objective of this study was to investigate the effects of biosolids addition, namely composted manure (MC) and activated sludge (AS), and spiking of the soils with orthophosphate (OP), phytic acid (PA) or humic acid (HA), on soil aggregate stability of semi-arid loamy sand, loam and clay soils before and after subjecting the soils to six rain storms (each 30 mm rain with a break of 3-4 days). Aggregate stability was determined from water-retention curves at high matric potential. The effects of the applied amendments on pre-and post-rain aggregate stability were inconsistent and soildependent. For the pre-rain state, all of the tested amendments improved aggregate stability relative to the control. For the post-rain condition, aggregate stability was lower in the MC, OP and PA treatments and higher in the AS and HA treatments than in the control. The coarse-textured loam and loamy sand soils were more affected by the soil amendments than the clay soil. For the pre-rain state, addition of organic matter significantly improved macro-porosity and hence the stability of apparent macro-aggregate (>250 mm). Our results indicate a possible advantage for separation of aggregates into macroand micro-aggregates for more precise evaluation and understanding of the effects organic amendments might have on aggregate stability.
The influence of organic matter on aggregate stability in some British soils
European Journal of Soil Science, 1984
The stability of aggregates from 26 soils selected from agricultural areas was measured by wet-sieving and the results correlated with sand, silt, clay, nitrogen, organic matter and iron contents and with cation exchange capacity. Highly significant correlations were obtained for the relationships between aggregate stability and organic matter and some properties associated with it. No other soil constituent investigated had a significant relationship with aggregate stability, indicating that organic matter is mainly responsible for the stabilization of aggregates in these soils.
Aggregate stability changes in a semiarid soil after treatment with different organic amendments
Arid Soil Research and Rehabilitation, 1996
Structural stability of soils is one of the most important characteristics related to soil degradation in semiarid areas. Organic additions can considerably improve soil structure and prevent soil degradation. In this experiment the effectiveness was compared of four types of organic amendments on the improvement of soil structure. The four treatments are sewage sludge, fresh uncomposted urban refuse, composted urban refuse, and horse manure. The uncomposted urban refuse was the most effective in increasing soil stable aggregates. The higher doses of sewage sludge and compost also improved aggregation of soil particles. Horse manure did not significantly improve soil aggregation. A significant correlation (τ = 0.955, ρ < 0.01) was found between fungal populations and stable aggregates. No significant correlations were found between stable aggregates in soil and the other parameters assessed. The organic treatments increasing soil microbial populations and promoting their activity appear to be very effective in improving soil structure.
Soil-aggregate formation as influenced by clay content and organic-matter amendment
Journal of Plant Nutrition and Soil Science, 2007
Naturally occurring wetting-and-drying cycles often enhance aggregation and give rise to a stable soil structure. In comparatively dry regions, such as large areas of Australia, organic-matter (OM) contents in topsoils of arable land are usually small. Therefore, the effects of wetting and drying are almost solely reliant on the clay content. To investigate the relations between wetting-and-drying cycles, aggregation, clay content, and OM in the Australian environment, an experiment was set up to determine the relative influence of both clay content (23%, 31%, 34%, and 38%) and OM amendments of barley straw (equivalent to 3.1 t ha -1 , 6.2 t ha -1 , and 12.4 t ha -1 ) on the development of waterstable aggregates in agricultural soil. The aggregate stability of each of the sixteen composite soils was determined after one, three, and six wet/dry cycles and subsequent fast and slow prewetting and was then compared to the aggregate stabilities of all other composite soils. While a single wet/dry cycle initiated soil structural evolution in all composite soils, enhancing macroaggregation, the incorporation of barley straw was most effective for the development of water-stable aggregates in those soils with 34% and 38% clay. Repeated wetting-and-drying events revealed that soil aggregation is primarily based on the clay content of the soil, but that large straw additions also tend to enhance soil aggregation. Relative to untreated soil, straw additions equivalent to 3.1 t ha -1 and 12.4 t ha -1 increased soil aggregation by about 100% and 250%, respectively, after three wet/dry cycles and fast prewetting, but were of less influence with subsequent wet/dry cycles. Straw additions were even more effective in aggregating soil when combined with slow prewetting; after three wet/dry cycles, the mean weight diameters of aggregates were increased by 70% and 140% with the same OM additions and by 160% and 290% after six wet/dry cycles, compared to samples without organic amendments. We suggest that in arable soils poor in OM and with a field texture grade of clay loam or finer, the addition of straw, which is often available from preceding crops, may be useful for improving aggregation. For a satisfactory degree of aggregate stability and an improved soil structural form, we found that straw additions of at least 6.2 t ha -1 were required. However, rapid wetting of straw-amended soil will disrupt newly formed aggregates, and straw has only a limited ability to sustain structural improvement.
Zemdirbyste-Agriculture, 2018
Soil water-stable aggregate (WSA) stability is one of the most important indicators of soil health, because it influences chemical, biological and other physical properties. At the same time, WSA formation, stabilization and degradation are also some of the most complex processes that occur in the soil, making them difficult to fully understand. In particular, there is a lack of research on WSA stability in the Baltic region. To gain a better understanding how aggregation occurs in Estonian pedo-climatic conditions, this study was conducted in 2014-2015 in a sandy loam Stagnic Luvisol (LV-st) (WRB, 2014). Potato and barley plots were analysed in a three-year crop rotation (potato → spring wheat → barley) with straw removal. The nitrogen (N) fertilization treatments were 0, 40, 80, 120 and 160 kg ha-1 yr-1 N, both without and with 40 Mg ha-1 fermented cattle farmyard manure (FYM) application prior to potato planting in the previous autumn. WSA stability was determined by Eijkelkamp's wet sieving apparatus from air-dried soil samples of less than 2 mm in diameter. The study revealed a negative correlation (r = −0.16) between increased N rates and WSA stability, regardless of FYM applications. Although soil organic carbon (SOC) content increased with additional N fertilization rates, the reduction in soil acidity (pH KCl) levels caused by N fertilization, most likely repealed the positive SOC content effect on WSA stability. In general, compared with sole N fertilization, FYM application had a positive effect on WSA stability. However, even though WSA stability did not always increase with FYM applications, it still had a positive effect on bulk density, SOC content and soil acidity levels. Further research is needed in Estonia due to the complexities involved in the soil aggregation process.
Compost Applications Increase Water-Stable Aggregates in Conventional and No-Tillage Systems
Soil Science Society of America Journal, 2003
ABSTRACT,two ways. First, fertilizers can increase crop production, leading to higher inputs of crop residues and more WSA Agricultural practices that alter the soil organic matter (SOM) than in unfertilized soils (Campbell et al., 2001). Second, content are expected to cause changes in soil stability and aggregation. soils amended,with organic fertilizers such as legume The objective of this study was