Biochar Enriched with Buffalo Slurry Improved Soil Nitrogen and Carbon Dynamics, Nutrient Uptake and Growth Attributes of Wheat by Reducing Leaching Losses of Nutrients

The present investigation was conducted to understand the role of enriched biochar on soil nitrogen and carbon dynamics, leaching losses of nutrients, and growth attributes of wheat. Buffalo slurry (BS) was used to enrich the biochar for 24 h and 2% biochar (SB) or enriched biochar (SEB) was used. Enrichment of biochar with BS as SEB improved the C and N contents of biochar by 33–310% and 41–286% respectively. The application of biochar (SB) and enriched biochar (SEB) reduced the net nitrification by 81% and 94%, ammonification by 48% and 74%, and carbon dioxide by 50% and 92% respectively as compared to control. The leaching losses minerals i.e., C (by 30%), N (by 125%), P (by 50%), K (by 82%), Na (by 9%), Ca (by 24%), and Mg (by 12%) was decreased in SEB treatments compared to control. The soil enzyme activities, microbial biomass (MBC and MBN), wheat agronomy, soil bulk density and soil pore density, mineral uptake from the soil, and mineral contents in the plant body were improved in the SEB as compared to SB and control treatments. Our results revealed that the biochar enrichment process could improve the C and N storage in the soil reservoir and lower the environmental risks to soil and water.

Valorization of Cotton Gin Trash through Thermal and Biological Conversion for Soil Application

Cotton gin trash, the by-product of the cotton ginning industry which is produced in large quantities every year, can be utilized as feedstock for deriving high quality organic materials such as biochar, compost and co-composted derivates for improvement of soils’ key physical, chemical and biological properties. This is the first report in which cotton gin trash was both thermally and biologically converted at the same time into biochar (BC), compost (C) and co-compost (Coc), and their effects on soil properties and on plant performance were examined. In order to find the optimum rate, the products were used as soil amendments in a greenhouse experiment at 2.5 t ha−1, 5 t ha−1and 10 t ha−1 rates. All of the amendments contributed in improving the soil properties and provided agronomic benefits to plants, however plants (radish var. Cherry belle) showed significantly (p < 0.05) better growth attributes and almost a 315% increase in biomass yield observed when co-composted biochar (10 t ha−1) was applied to the soil, thus suggesting its role in compensating fertilizer application. Amendments (2.5 and 5.0 t ha−1) considerably increased plant growth parameters; however, differences between 5 and 10 t ha−1 amendments were not so significant. As a result, replenishing soil with Coc (5 t ha−1) on a regular basis can promote plant growth and improve soil qualities over time.

Application of Zinc and Iron-Based Fertilizers Improves the Growth Attributes, Productivity, and Grain Quality of Two Wheat (Triticum aestivum) Cultivars

Field-based experiments were conducted during wheat cultivation seasons of 2017–2018 and 2018–2019 to minimize the impact of hidden hunger (micronutrient deficiencies) through agronomic biofortification of two wheat cultivars with zinc and iron. Two spring-planted bread wheat cultivars: Zincol-16 (Zn-efficient) and Anaj-17 (Zn-inefficient with high-yield potential) were treated with either zinc (10 kg/ha), iron (12 kg/ha), or their combination to study their effect on some growth attributes (plant height, tillers, and spike length, etc.,), productivity, and quality. No application of zinc and iron or their combinations served as the control. Maximum Zn and Fe contents of grains were improved by sole application of Zn and Fe, respectively. A higher concentration of Ca in grains was observed by the combined application of Zn and Fe. Starch contents were found maximum by sole application of Fe. Sole or combined application of Zn and Fe reduced wet gluten contents. Maximum proteins were recorded in Anaj-17 under control treatments. Zincol-16 produced maximum ionic concentration, starch contents, and wet gluten as compared to Anaj-17. Yield and growth attributes were also significantly (p &lt; 0.05) improved by combined application as compared to the sole application of Zn or Fe. The combined application also produced the highest biological and grain yield with a maximum harvest index. Cultivar Anaj-17 was found more responsive regarding growth and yield attributes comparatively. The findings of the present study showed that the combined application of Zn and Fe produced good quality grains (more Zn, Fe, Ca, starch, and less gluten concentrations) with a maximum productivity of bread wheat cultivars.

The impact of different growth media and ammonium-nitrate ratio on yield and nitrate accumulation in lettuce (Lactuca sativa var. longifolia)

Ammonium (NH4+) to nitrate (NO3-) ratio and growth media significantly alter plant development and NO3- accumulation in lettuce. Nitrate accumulation is regarded harmful for environment and human health. The quality of lettuce is assessed by NO3-concentration, size, and weight. This study determined the impact of five different growth media (cocopeat, peat, bark, perlite and rockwool) and four different NH4+:NO3- ratios (0:100, 20:80, 40:60 and 60:40) on NO3- accumulation in lettuce, yield, and several growth attributes. The experimentation was conducted according to open feeding system of soilless agriculture. The ‘Cosmos’ variety of lettuce was used as experimental material in the study. Growth mediums and NH4+:NO3- ratios significantly altered NO3- accumulation, head, leaf, stem and root traits. The results revealed that instead of growing lettuce with NO3- only in peat and rockwool, addition of NH4+ (20:80 of NH4+:NO3-) into nutrient solution increased head weight. While head weight increased in perlite medium with the addition of NH4+, it decreased in cocopeat and bark media. It is concluded that growth media and NH4+:NO3- ratios pose significant impacts on NO3- accumulation in leaf and that the increase in NH4+ ratio decreased NO3- accumulation in all growing media. Therefore, it is recommended that NH4+ should be added in the nutrient solution to decrease NO3- accumulation, which will ultimately improve yield and quality of lettuce.

Calibration and Validation of DSSAT CROPGRO Peanut Model for Yield and Yield Attributing Characters of Groundnut Varieties in Northern Agro-Climatic Zone of Tamil Nadu

Aim: The research study was conducted to calibrate and validate the DSSAT CROPGRO peanut model for simulating the potential yield of groundnut to deciding the best possible management options at major growing areas of Northern Agro-Climatic zone of Tamil Nadu. Study Design: The experiment was conducted in Split plot Design with four Sowing dates and cultivars. Methodology: The DSSAT model requires layer wise soil data (physical and chemical), including soil texture and other soil properties. Daily weather data, including maximum and minimum air temperature (°C), solar radiation (MJ m−2 day−1), Relative Humidity (%) and precipitation (mm) were used as inputs. Data describing management practices and information of cultivar-specific genetic coefficients were used to calibrate the model. Validation of model were carried out using observed growth and yield attributes of TMV13 and G7 varieties using RMSE (Root Mean Square Error), NRMSE (Normalized Root Mean Square Error) and agreement per cent as test criteria for the evaluation. Results: The performance of DSSAT CROPGRO peanut model for simulated growth attributes were underestimated the growth attributes like days to anthesis, leaf area index, days to first pod and days to maturity than compared to observed growth attributes of TMV13 and G7 varieties. But the model performs better for G7 as compared to TMV13. Whereas, yield and yield attributes of CROPGRO peanut model were overestimated than the observed yield. Conclusion: The simulation model shows the low RMSE, NRMSE and high agreement per cent for growth and yield of groundnut which was more than 90 per cent, it shows the higher level of confidence on model simulation with observed characters.

Application of sewage sludge combined with thiourea improves the growth and yield attributes of wheat (Triticum aestivum L.) genotypes under arsenic-contaminated soil

Arsenic (As) contamination is a serious threat to agriculture and human health worldwide. It can adversely affect the growth attributes of food crops. On the other hand, using thiourea (TU) to ameliorate As stress is an economically consistent approach. However, there is a knowledge gap regarding the combined use of TU and Sewage sludge (SS). SS is considered important, unutilized biomass. It can be used as a fertilizer that has high organic matter and nutrients. Therefore, the current study was performed to evaluate TU and SS sole and combined responses under As toxicity on two wheat genotypes (Markaz 19 and Ujala 16). There were four treatments control (As 50 mg kg-1), SS (30 g kg−1)+TU (6.5 mM)+As, TU+As and SS+As applied with four replications. Results revealed that SS+TU performed significantly better over SS, TU and control for improvement in root and shoot fresh and dry weight of wheat varieties Markaz 19 and Ujala 16 under As toxicity. A significant decrease in POD, SOD and APX of Markaz 19 and Ujala 16 also validated the effective functioning of SS+TU over control. The maximum increase of 71 and 77% was noted in phosphorus, where SS+TU was applied over control in Markaz 19 and Ujala 16, respectively. In conclusion, SS+TU is a better approach than the sole application of SS and TU under As contamination for improvement in wheat growth attributes. More investigations are recommended at the field level under different As contamination and agro-climatic zones to declare SS+TU an effective amendment to mitigate As toxicity in wheat.