Search

The reaction of H2PO42- and HPO4- with Al and Fe in acid soils to form a precipitate reduces P availability. Chicken litter biochar has been used to improve soil P availability for maize production but with limited information on optimum rates of biochar and Triple Superphosphate (TSP) to increase P availability. This study determined the optimum amount of chicken litter biochar and TSP that could increase P availability. Different rates of chicken litter biochar and TSP were evaluated in an incubation study for 30, 60, and 90 days. Selected soil chemical properties before and after incubation were determined using standard procedures. Soil pH, total P, available P, and water soluble P increased in treatments with 75% and 50% biochar. Total acidity, exchangeable Al3+, and Fe2+ were significantly reduced by the chicken litter biochar. The chicken litter biochar also increased soil CEC and exchangeable cations (K, Ca, Mg and Na). The use of 75% and 50% of 5 t ha-1 biochar with 25% TSP of the existing recommendation can be used to increase P availability whilst minimizing soil Al and Fe content. This rates can be used to optimize chicken litter biochar and TSP use in acid soils for crop production especially maize and short term vegetables.

Co-composting of chicken slurry and rice straw with clinoptilolite zeolite and urea as additives was conducted to determine the characteristics of a compost and their effects on controlling ammonium (NH4+) and nitrate (NO3−) losses from urea. Quality of the compost was assessed based on temperature, moisture content, ash, pH, electrical conductivity, carbon/nitrogen (C/N) ratio, NH4+, NO3−, macronutrients, heavy metals, humic acid, microbial population, germination index, and phytotoxicity test. Moisture content and C/N ratio of the compost were 43.83% and 15, respectively. Total N, humic acid, ash, NH4+, NO3−, phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) increased after co-composting rice straw and chicken slurry. Copper, iron (Fe), manganese (Mn), zinc (Zn), and microbial biomass of the compost were low. The germination rate of Zea mays on distilled water and Spinacia oleracea growth on peat-based growing medium (PBGM) and compost were not significantly different....

Peat soils have been developed for large scale plantations such as oil palm due to their positive contribution to Malaysia’s economic growth in agriculture sector. However, these developments contribute to the emissions of greenhouse gases (GHGs) mainly carbon (CO2) and methane (CH4). To date, there were limited information of GHGs emissions from pineapple cultivation and also inadequate data on horizontally and vertically soil GHGs emissions in peat soil profile. Thus, this study was carried out to determine carbon CO2 and CH4 emissions horizontally and vertically from a drained tropical peat soils from a drained tropical peat soils cultivated with pineapple (Ananas comosus (L.) Merr. Horizontal and vertical movements of CO2 and CH4 were measured from a drained tropical peatland with Ananas comosus (L.) Merr. Tropical peat soils cultivated with Ananas comosus (L.) Merr. contributed to 79.7 % of CO2, and 0.2 % of CH4 based on the yearly basis regardless of the differences in diurnal transportation; horizontal and vertical emission. Soil CO2 and CH4 were emitted the most through horizontal transportation with 70.84 % CO2, and 0.19 % CH4 compared to 8.85 % CO2, and 0.02 % CH4 in vertical transportation. The emission of CO2 was influenced by depth of water table and temperature. It is generally believed that lowering of peats water table leads to emission of higher CO2 emission because this process leads to exposure of peat soils to oxidation. Seasonal variation in CH4 flux was higher in the wet seasons due to rainfall; this might have increased the water table of the peat soil. The results suggest that CO2 and CH4 emissions occur both horizontally and vertically regardless of season. Therefore in order not to underestimate CO2 and CH4 emissions from peat soil, it is important to measure the emissions of this greenhouse gas which has been implicated in environmental pollution horizontally and vertically.

Although urea use in agriculture is on the increase, increase in pH at soil microsite due to urea hydrolysis which causes ammonia emission can reduce N use efficiency. Among the interventions used to mitigate ammonia loss include urease inhibitors, clinoptilolite zeolite, coated urea, and biochar but with little attention to the use of soil water levels to control ammonia volatilization. The objective of this study was to determine the effects of soil water levels on ammonia volatilization from soils with and without chicken litter biochar. Dry soils with and without chicken litter biochar were subjected to 0%, 25% 50%, 75%, 100%, and 125% soil water. There was no urea hydrolysis in the soil without water. Chicken litter biochar as soil amendment effectively mitigated ammonia loss at 1% to 32% and 80% to 115% field capacity. However, urea used on soil only showed lower ammonia loss at 33% to 79% and 116% to 125% field capacity compared with the soils with chicken litter biochar. At 50% field capacity ammonia loss was high in soils with and without chicken litter biochar. Although chicken litter biochar is reputed for improving soil chemical properties, water levels in this present study affected soil chemical properties differently. Fifty percent field capacity, significantly reduced soil chemical properties. These findings suggest that timely application of urea at the right field capacity can mitigate ammonia emission. Therefore, whether soils are amended with or without chicken litter biochar, urea application should be avoided at 50% field capacity especially in irrigated crops.

In production agriculture, granular urea is the most used nitrogen fertilizer in crop production. However, increase in soil pH following application of urea causes ammonia volatilization and reduces N use efficiency. To minimize ammonia loss, organic amendments are used, however, type of organic amendment use could affect urea use efficiency. This study was to determine the effects of organic amendments derived from forest litter, Leucaena leucocephala, chicken litter, and cow dung on ammonia volatilization and chemical properties of a waterlogged acid soil. Treatments evaluated were: (i) T1, Soil only, (ii) T2, Existing recommended fertilization, (iii) T3, Biochar-forest litter compost, (iv) T4, Biochar-chicken litter compost, (v) T5, Biochar-cow dung compost, (vi) T6, Biochar-Leucaena compost, and (vii) T7, Biochar-Leucaena - chicken litter compost. Standard procedures were used to quantify ammonia volatilization and soil chemical properties. The findings of this present study also revealed that the total amount of ammonia loss from urea over a period of forty-two days depends on the influence of the organic amendments on urea hydrolysis. Emissions of ammonia from T6 and T7 were significantly higher because, the decomposition of Leucaena leucocephala favours urea hydrolysis compared with those of T3, T4, and T5. Therefore, Leucaena leucocephala composts should be carefully co-applied with urea to minimize ammonia loss if the aim of using this type of amendments is to improve N use efficiency and soil and crop productivity.

Excessive uses of fertilizer can create environmental problems such as soil pollution. This problem could be reduced by amending clinoptilolite zeolite with compound fertilizers. The objective of this study was to evaluate the effect of clinoptilolite zeolite rates in compound fertilizers (N: P: K) on maize nutrients uptake and use efficiency. The following treatments were considered and evaluated: soil alone (T1), 44.6 g 5:3:2 formulated fertilizer (12.83 g compound fertilizer + 31.77 g zeolite) (T2), 44.6 g 5:5:5 formulated fertilizer(18.24 g compound fertilizer + 26.36 g zeolite) (T3), 37.17 g 6:6:6 formulated fertilizer (18.25 g compound fertilizer + 18.92 g zeolite) (T4), 22.30 g 10:10:10 formulated fertilizer (18.24 g compound fertilizer + 4.06 g zeolite) (T5), and 14.87 g 15:15:15 commercial fertilizer (T6). Selected soil chemical properties, as well as, dry weight, nutrients concentrations, uptake and use efficiency were measured. Compound fertilizers with zeolite increased soil pH compared to soil alone (T1) and commercial fertilizer (T6). Application of compound fertilizer did no significantly affect total N and available nitrate in the soil. T6 gave better plant height and dry matter production among treatments. Nitrogen concentrations for all plant parts were similar for all treatments. T6 showed better P concentrations, uptake, and use efficiency. K concentrations in maize plant parts were significantly increased for treatments with zeolite except for roots. T5 and T6 significantly increased K uptake. T6 significantly increased N and P uptake and use efficiency, while T2 significantly increased K use efficiency. Amending N, P, and K fertilizers with higher dosage of clinoptilolite zeolite improved soil chemical properties, nutrient uptake of Masmadu variety. Compound fertilizers amended with clinoptilolite zeolite enhanced K use efficiency of Masmadu maize variety.