Dynamics of multiple elements in fast decomposing vegetable residues (original) (raw)
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Dynamics of plant residue decomposition and availability of nutrients
International Journal of Chemical Studies, 2020
An experiment in relation to "Dynamics of plant residue decomposition and availability of nutrients" was conducted during the months of August to December of the year 2018 in Soil Science and Agricultural Chemistry Section, College of Agriculture, Nagpur. The study includes CO2 evolution study as well as availability of nutrients. Different organic residues like cowdung, paddy straw, wheat straw, sugarcane trash, gliricidia loppings, subabul leaves, soybean stalks and green gram stalks were used in the investigation. CO2 evolution was high on the first day and then it attained an approximately steady rate of evolution up to 10 th day. Thereafter, it started increasing with a considerable amount and reached the peak on 8 th week from where it declined till 120 th day. From the cumulative CO2 evolution of different mixtures, it was found that the highest evolution was generated by green gram stalks mixture (T9) and lowest was recorded by control pot (T1). Nutrient availability was also influence significantly due to different organic residues. The subabul leaves mixture was found superior among the others with respect to available nitrogen content (170.49 kg ha-1) and highest P content (16.69 kg ha-1) was found in Gliricidia lopping mixture. Where as green gram stalks mixture recorded highest potassium i.e., 395.2 kg ha-1 .
Acta Oecologica-international Journal of Ecology, 2003
The decomposition dynamics of four types of needle litter and three types of leaf litter were followed for 3 years at two very contrasting coniferous forest systems, a nutrient-rich silver fir (Abies alba Mill.) forest in south Italy (Monte Taburno) and a nutrient-poor Scots pine (Pinus sylvestris L.) forest in central Sweden (Jädraås). Decomposition of the same litter type at the two sites did not differ in the early stages but proceeded further at the nutrient-rich forest site than at the nutrient-poor one. Limit values for decomposition were calculated and the differences for the same litter type between the two contrasting coniferous systems were investigated. At both sites six of the seven litter types gave significant (asymptotic) limit values for decomposition, which varied with litter type. For four litter types out of six the limit values differed significantly between the two sites and were always higher at the nutrient-rich site (Monte Taburno). Using all available data for litters incubated at the two sites revealed that at the nutrient-poor site (Jädraås) there was a significant negative relationship between litter N levels and limit values and there was also a significant negative relationship between initial concentrations of heavy metals (e.g. Zn, Cd, Cu) and limit values. In contrast, at the site Monte Taburno, rich in nutrients and in heavy metals, there was no such relationship.
Early stage litter decomposition across biomes
The Gascogne region (SW of France) is cultivated for more than 75% of the area. 83 samples of stream bed sediments were collected in three main Gascogne river basins (Gers, Save and Touch, left tributaries of the Garonne river) to evaluate the impact of agricultural practices on trace elements behavior. Eight potential harmful elements (PHE) (Cr, Co, Ni, Cu, Zn, As, Cd and Pb), four reference elements for normalization (Sc, Cs, Al and Fe) and four major elements (Mn, Ca, Mg and P) were considered. The average trace element concentrations in the fine fractions (b63 µm) are in the decreasing order: Zn N CrN NiN Pb N Cu N CoN AsN ScN CsN Cd. Geochemical investigations and an original approach combining regression analysis and chemical sequential extraction allowed to select the most adequate reference material (regional molasse) and reference element (Cs) for normalization procedure. The enrichment factor (EF) is generally lower than 2.5, particularly for Cr, Ni, Cu, As, Zn; however, 23% of the sampling stations are more contaminated (2.5 b EFb 4.5), particularly for Cd, Pb and Co. The PHE in the Gascogne river sediments are mainly originated from natural weathering processes; nevertheless, anthropogenic contribution could represent up to 34% of the total sediment content. For lead, geochemical and isotopic methods gave very similar anthropogenic contributions (24% and 22%, respectively). The enrichment of Cu, Pb, Zn, Co, As, Ni, Cr was mainly related to global and local atmospheric deposition of industrial emissions and gasoline combustion, and was associated to forested catchments. All PHE's are controlled by clay and oxi-hydroxides minerals. Cd was the only PHE enriched downstream cultivated catchments and this enrichment was linked to Ca and P. This indicates a major origin of Cd from fertilizer inputs and a main control by carbonate minerals.
Fate of particulate organic matter in soil aggregates during cultivation
European Journal of Soil Science, 1996
Particulate organic matter (POM) is a labile fraction of soil organic matter which is thought to be physically protected from biodegradation when within soil aggregates. We have developed a fractionation method to separate POM located outside stable soil macroaggregates (> 200 pm) and microaggregates (50-200 pm) from that within them, and applied it to a cultivation sequence of humic loamy soils. The natural abundance of 13C was used to determine the amounts of POM derived from forest and that derived from crop in the free and occluded fractions. In the forest soil the free and occluded POM fractions had the same composition, morphology and isotopic signature. On cultivation the amounts of POM decreased sharply. The loss of C in the POM from forest was mainly from POM outside the aggregates. The POM occluded within microaggregates was found to turnover slowly. This may be due either to its recalcitrant chemical nature or to its physical protection within microaggregates Dynamique des mati&res organiques particulaires dans les agrCgats de sol lors d'une mise en culture
Interactions between decomposition of plant residues and nitrogen cycling in soil
Plant and Soil, 1996
The processes of N mineralization and immobilization which can occur in agricultural soils during decomposition of plant residues are briefly reviewed in this paper. Results from different incubation studies have indicated that the amounts of N immobilized can be very important and that the intensity and kinetics of N immobilization and subsequent remineralization depend on the nature of plant residues and the type of decomposers associated. However, most of the available literature on these processes refer to incubations where large amounts of mineral N were present in soil.
Soil Biology and Biochemistry, 1999
On 12 occasions during a 2-y ®eld experiment, we determined the decomposition of barley straw, ryegrass foliage, white clover foliage, potato haulm and white cabbage leaves con®ned in buried mesh bags that were protected against leaching. After 1 y, 49, 18, 8, 25 and 5% of initial carbon in the ®ve crop residues remained, respectively. The corresponding ®gures for nitrogen were 105, 32, 8, 36 and 11%. The data were used to evaluate a simulation model developed during previous studies of crop residue C and N turnover under controlled temperature and moisture conditions. Description of plant residue degradability and model parameter values were taken from these studies. Rate-modifying functions were then added to take account of eects of measured soil temperature and moisture. The model gave a good overall description of crop residue degradation but underestimated C release and, to a greater extent, N release during the ®rst autumn and winter. The relatively rapid N loss during this period, suggested that low temperatures restricted microbial N immobilization more than it did gross decomposition. We hypothesized that this was caused by a reduced microbial growth yield eciency (E) at low temperatures. When we reduced the value of E from 0.5 (default value) to 0.2 at 28C and below, model ®t to C and N mineralization was improved substantially. Moreover, the model produced an excellent ®t to remaining wheat straw C and a gave good description of N mineralization in an independent experiment, indicating that reducing the value of E was justi®ed. The results suggested that crop residue degradability and the decomposer community were reasonably described in the model, that the rate-modifying functions of temperature, moisture and N availability were sound and that parameter values set under controlled conditions also represented ®eld conditions, possibly with the exception of E.