Search

Developing successful mitigation strategies for greenhouse gases (GHGs) from crop residue returned to the soil can be difficult due to an incomplete understanding of factors controlling their magnitude and direction. Therefore, this study investigates the effects of varying levels of wheat residue (WR) and nutrient management on GHGs emissions (CO2, N2O, and CH4) across three soil types: Alfisol, Vertisol, and Inceptisol. A combination of laboratory-based measurements and a variety of data analysis techniques was used to assess the GHG responses under four levels of WR inputs (0, 5, 10, and 15 Mg/ha; WR0, WR5, WR10, and WR15) and three levels of nutrient (NP0: no nutrient, NP1: nutrients (N and P) were added to balance the residue C/nutrient stoichiometry of C/N/P= 100: 8.3: 2.0 to achieve 30% stabilization of added residue C input at 5 Mg/ha (R5), and NP2: 3 × NP1). The results of this study clearly showed that averaged across residue and nutrient input, Inceptisol showed negative N2O flux, suggesting consumption which was supported by its high legacy phosphorus (19.7 mg kg⁻1), elevated pH (8.49), and lower clay content (13%), which reduced microbial activity, as indicated by lower microbial biomass carbon (MBC) and alkaline phosphatase (Alk-P) levels. N2O emissions were more responsive to nutrient inputs, particularly in Vertisol under high WR (15 Mg/ha) input, while CH4 fluxes were significantly reduced under high residue inputs, especially in Vertisol and Inceptisol. Alfisol exhibited the highest total carbon mineralization and GWP, with cumulative GWP being 1.2 times higher than Vertisol and 1.4 times higher than Inceptisol across residue and nutrient input. The partial least square (PLS) regression revealed that anthropogenic factors significantly influenced CO2 and N2O fluxes more than CH4. The anthropogenic drivers contributed 62% and 44% of the variance explained for N2O and CH4 responses. Our study proves that different biogeochemical mechanisms operate simultaneously depending on the stoichiometry of residue C and nutrients influencing soil GHG responses. Our findings provide insight into the relative contribution of anthropogenic and natural drivers to agricultural GHG emissions, which are relevant for developing process-based models and addressing the broader challenge of climate change mitigation through crop residue management. [ABSTRACT FROM AUTHOR]

Low nutrient use efficiency (NUE) of conventional chemical fertilizers has resulted in the loss of costly nutrients and related environmental implications. Consequently, enhancing crop productivity and nutrient use efficiency are major challenges. In this backdrop, a field experiment was conducted to study the impact of pine oleoresin (POR) and neem oil (NO) coated urea (CU) fertilizers on crop productivity and nutrient recovery efficiency in maize-wheat cropping system grown on Vertisols of central India. The treatment combinations were POR-CU and NO-CU at 100% and 75% of recommended doses of fertilizers (RDF); normal urea (100% RDF); and an unfertilized control. Two years results indicated that the increment in grain yields due to POR-CU and NO-CU applications were 18.8% and 11.7% for maize and 11.6% and 3.49% for wheat, respectively, over normal urea. The apparent recovery efficiency of N (REN) for PORCU, NO-CU, and normal urea at 100% RDF were 65.8%, 64.2%, and 51.4% in maize and 43.2%, 37.0%, and 34.6% in wheat, respectively. There was no significant difference noticed between POR-CU and NO-CU with respect to grain yield and N recovery efficiency. Hence, the study suggested that POR-CU could be a possible alternative option to NO-CU for improving crop yield and NUE. However, further research is needed to determine how effective POR-CU is in diverse agricultural systems and climatic conditions. [ABSTRACT FROM AUTHOR]

A laboratory incubation experiment was conducted for 36 days to study the effect of pigeon pea biochar (PPB) and wood biochar (WB) on carbon mineralization of native soil organic carbon (SOC) and municipal solid waste compost (MSWC) applied to soil. The MSWC addition enhanced soil respiration by 2-fold (231 mg C kg-1 soil) over the control (118 mg C kg-1 soil). The PPB addition significantly (P < 0.05) increased cumulative loss of carbon as CO2, whereas WB significantly decreased the cumulative loss of C over control. Addition of PPB at 5% and 10% levels increased SOC mineralization (positive priming) +22.9% and +31.2%, respectively; whereas reduction in SOC mineralization (negative priming) was noticed in WB (5% and 10%) treated soils by -3.1% and -21.7%, respectively. Similarly, WB induced strong negative priming effects (-21.9% and -29.5%), while PPB caused a weak positive priming effect (+3.0% and +11.6%) at 5% and 10% levels on mineralization of added labile carbon substrate (MSWC), respectively. Results indicate the hardwood (Prosopis juliflora) biochar exhibits refractory properties that inhibit mineralization of both native SOC and applied organic compost (MSWC), and thereby it can be used as an amendment to stabilize native and applied organic matter in soil, which may significantly contribute to soil carbon sequestration. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions from agricultural production systems are a major area of concern in mitigating climate change. Therefore, a study was conducted to investigate the effects of crop residue, nutrient management, and soil moisture on methane (CH4) emissions from maize, rice, soybean, and wheat production systems. In this study, incubation experiments were conducted with four residue types (maize, rice, soybean, wheat), seven nutrient management treatments {N0P0K0 (no nutrients), N0PK, N100PK, N150PK, N100PK + manure@ 5 Mg ha−1, N100PK + biochar@ 5 Mg ha−1, N150PK+ biochar@ 5 Mg ha−1}, and two soil moisture levels (80% FC, and 60% FC). The results of this study indicated that interactive effects of residue type, nutrient management, and soil moisture significantly affected methane (CH4) fluxes. After 87 days of incubation, the treatment receiving rice residue with N100PK at 60% FC had the highest cumulative CH4 mitigation of −19.4 µg C kg−1 soil, and the highest emission of CH4 was observed in wheat residue application with N0PK at 80% FC (+12.93 µg C kg−1 soil). Nutrient management had mixed effects on CH4 emissions across residue and soil moisture levels in the following order: N150PK > N0PK > N150PK + biochar > N0P0K0 > N100PK + manure > N100PK + biochar > N100PK. Decreasing soil moisture from 80% FC to 60% FC reduced methane emissions across all residue types and nutrient treatments. Wheat and maize residues exhibited the highest carbon mineralization rates, followed by rice and soybean residues. Nutrient inputs generally decreased residue carbon mineralization. The regression analysis indicated that soil moisture and residue C mineralization were the two dominant predictor variables that estimated 31% of soil methane fluxes in Vertisols. The results of this study show the complexity of methane dynamics and emphasize the importance of integrated crop, nutrient, and soil moisture (irrigation) management strategies that need to be developed to minimize methane emissions from agricultural production systems to mitigate climate change. [ABSTRACT FROM AUTHOR]

The Indian Grey Wolf Canis lupus pallipes is an iconic species of grassland in India. It is a Schedule 1 species according to the Wildlife Protection Act, 1972 and CITES Appendix 1 species. In the absence of parental care, five wolf pups were rescued from Baavarla on 26 November 2020 and brought into Machia Biological Park for hand rearing. In the absence of colostrum, a milk replacer formula (PetLac) was provided to the pups. The pups were kept at an ambient room temperature of 101°F as an adjustment to their natural surroundings. Gripe water, Vitamin A, and multivitamins were administered orally. The temperature and body growth parameters were measured and recorded weekly. Rabies vaccine was administered in the 26th week from the date of rescue. The diet of the wolf was gradually changed and from the 37th week, raw meat was included in their diet. Antibiotics Ciplox-TZ (ciprofloxacin and tinidazole tablet) Brand-Cipla and SPORLAC-DS (lactic acid bacillus tablets 120M) Brand-sanzyme Ltd. were given periodically to restore the gut fauna of the pups. [ABSTRACT FROM AUTHOR]

A large amount of waste material and tailings, generated from opencast mineral extraction, released different heavy metals and metalloids that polluted the mine surroundings soil. In the present investigation, an attempt was made to revegetate the open-cut mine affected area. Bulk soil samples were collected from derelict Frogmore tungsten mine site, and after physicochemical characterization of the soil samples, pot culture experiments were conducted in a green house. The different experimental soils like control soil, polluted soil, and polluted soil treated with the combined amendment, viz. Nano chailings (8 t/ha) + Nano composite of Zeolites + Nano Clay (Bentonite) (5%) + Nano composite of Zeolite + Zero valent iron (5%) + 5 t/ha FYM (Farm Yard Manure), were used in the investigation and maize (Zea mays L.) was taken as a test crop. This paper focused on amendments based on nano-enhanced materials. Amongst heavy metals like Cd, Ni, Zn, Cu, Pb, etc., Pb recorded the highest amount (125 mg/kg), which caused drastic reduction in different growth parameters of maize plant grown in mine spoiled soil. Microscopic structural changes, such as decrease in intercellular spaces, stomatal opening, shrinkage of palisade and epidermal cells, occurred in maize leaves grown in the mine polluted soil. Experimental results also revealed significant decrease in the fresh weight, dry weight, height, and girth of maize plants grown in mine spoiled soil. The contaminant distribution in the mine site should be considered in the design of management and remediation strategies. The possible practical consequences of these findings might be the application of nano-enhanced materials for the remediation and revegetation of the abandoned mine spoiled soils. [ABSTRACT FROM AUTHOR]

In the present investigation, an attempt was made to determine the direct effects of fertilizers on various soil properties like acidification, organic matter content, the content of essential and toxic trace metals in soils and food grains under long term (>25 years) fertilizer experiment. Soil and plant samples were collected from Bengaluru center of All India Coordinated Research Project on Long-Term Fertilizer Experimental site in the sub-regions AESR 8.1 of India, with the treatments e.g. control, 100% N, 100% NP, 100% NPK, 150% NPK, 100% NPK + Lime, 100% NPK+ farmyard manure (FYM) at 0 to 60 cm depth with an interval of 15 cm. Laboratory analysis was conducted to know the vertical distribution of heavy metals and micronutrient cations in soil and plant produce by following the standard method. The DTPA soil Zn remained unchanged with the higher rates of N application, i.e. 100% N. There was very little effect of N, NP, and NPK application on the buildup of DTPA-able Zn, Fe, Mn, and Cu content in both the soils. However, the application of NPK + FYM showed a buildup in comparison to control for Fe 10 mg kg−1, Mn 18 mg kg−1, Zn 1.23 mg kg−1, and Cu 0.84 mg kg−1 in soil. Continuous fertilizer application contributed a meager amount accumulation of Cd, Pb, Ni, Co, and Cr in the soil under the finger millet – maize cropping sequence. The estimation of heavy metals in food grains, supposed to come from fertilizers, lime materials applied in soil was also of our concern. All the cited heavy metals were present in the maize and finger-millet grains. Risk assessment to human health (Hazard Quotient, HQ) for the intake of heavy metals through consumption of contaminated food grains was computed and observed that the values of 'HQ' for all the crops were far less than unity (<1) and safe for the consumers. [ABSTRACT FROM AUTHOR]

In India, zinc (Zn) has been recognized as the fourth most important yield-limiting nutrient after nitrogen (N), phosphorus (P) and potassium (K). Supplementing the zinc (Zn) requirement of agricultural crops through water soluble zinc sulfate ZnSO4 fertilizer is a costly management option whereas, utilization of ZnO (water insoluble and a cheaper material) as a source of Zn could be an alternative cost effective option to encourage farmers for wider adoption. In this present investigation, in order to supply the requisite amount of Zn to the plants, a protocol has been developed to coat the seeds of maize (Zea mays L.), soybean (Glycine max L.), pigeon pea (Cajanas cajan L.) and ladies finger (Abelmoschus esculentus L.) with microns scale (<3 µm) and nano-scale (<100 nm) ZnO powder at 25 mg Zn/g seed and at 50 mg Zn/g seed. Different Zn sources, ethyl alcohol, and crude pine oleoresin (POR) were used for coating of seeds. The germination test carried out with coated and uncoated seeds indicated better germination percentage (93–100%) due to ZnO coating as compared to uncoated seeds (80%). Pot culture experiment conducted with coated seeds also revealed that the crop growth with ZnO coated seeds were similar to that observed with soluble Zn treatment applied as zinc sulfate heptahydrate (ZnSO4·7H2O) (at 2.5 ppm Zn) which is evident from the periodic SPAD reading taken after 20, 25, 30 and 45 days after sowing. Application of Zn through different sources also enhanced the auxin indole-3-acetic acid (IAA) production in plant roots, which subsequently improved the overall growth. The most important advantage of seed coating with ZnO (both micron/nano-scale) is that it did not exert any osmotic potential at the time of germination of the seed, thus, the total requirement of Zn of the crop can be loaded with the seed effectively through nano-scale ZnO particle. [ABSTRACT FROM AUTHOR]