Psidium guajava (L.)—a Bioeconomic Plant for Restoration of Industrial Solid Waste Dump: a Green and Sustainable Approach

Water, Air, & Soil Pollution - Air pollution, especially heavy metals in PM2.5, has gradually become one of the most serious environmental problems in cities, which might cause various...     

Soil organic carbon pools and productivity in relation to nutrient management in a 20-year-old rice–berseem agroecosystem

Labile fractions of soil organic C (SOC) can respond rapidly to changes in C supply and are considered to be important indicators of soil quality. An attempt is made in this paper to investigate into the dynamics of total organic C (C _tot), oxidisable organic C (C _oc), very labile C (C _{frac 1}), labile C (C _{frac 2}), less labile C (C _{frac 3}), non-labile C (C _{frac 4}), microbial biomass C (C _mic), mineralizable C (C _min) and particulate organic C (C _p) in relation to the system productivity of a 20-year-old rice (Oryza sativa L)–berseem (Trifolium alexandrium L) cropping system with different management strategies [no fertilization, only NPK and NPK + FYM (farmyard manure) applied in different seasons] in the hot humid, subtropics of India. Cultivation over the years caused a net decrease, while balanced fertilization with NPK maintained the SOC. About 62% of the C applied as FYM was stabilized into SOC. The passive pool (C _{frac 3} + C _{frac 4}) constituted about 55% of the C _tot. A larger proportion (63%) of applied C was stabilized in the passive pool of SOC. Of the analysed pools, C _{frac 1}, C _mic, C _p and C _min were influenced most by the treatments imposed and explained higher per cent variability in the yield of the crops.     

Impact of neem (Azadirachta indica A. Juss) seed cake upon selective nutrient cycling bacterial population in fish culture

With an objective to examine neem seed cake as bactericide, three treatments—10, 20, and 30 mg L^?1—were applied in outdoor experimental Labeo rohita culture tanks for a period of 120 days. Nitrifying, ammonifying, and denitrifying bacteria declined directly with increasing dosage. Ammonifying and phosphate solubilizing bacteria recovered within a month, nitrifying and denitrifying bacteria after 45 days. A positive relationship was established between soil available-N and ammonifying, nitrifying, and denitrifying bacteria in 10 mg L^?1 (R² = 0.68–0.83). Phosphate solubilizing bacteria responded directly with dosage and contributed significantly to the orthophosphate pool (R² = 0.66–0.78).