Quantification of yield gaps in rain-fed rice, wheat, cotton and mustard in India

Rainfed farming / Crop yield / Simulation / Rice / Wheat / Cotton / Mustard / India

Physico-Chemical Characterization Of Sweet Chestnut (Castanea Sativa L.) Starch Grown In Temperate Climate Of Kashmir, India

Studies were conducted to characterize the chestnut starch for physico-chemical properties. Chemical composition of chestnut starch showed low levels of protein and ash indicating purity of starch. The results revealed low water and oil absorption capacity of chestnut starch. Starch showed high swelling power and low solubility index. Swelling power and solubility index of chestnut starch increased with increase in temperature (50–90 °C). The results revealed high initial, peak, setback, breakdown, and final viscosity but low paste development temperature. Transmittance (%) of the starch gel was low and decreased with increasing storage period. The chestnut starch gel showed increase in % water release (syneresis) with increase in time of storage but was less susceptible to repeated cycles of freezing and thawing. Starch was also characterized for granule morphology. Starch granules were of round and oval shapes, some granules showed irregular shape

Hydrological consequences of cultivating Jatropha crop in degradable waste lands of India and ecosystem trade-offs at watershed scale

Biofuel production from feedstocks grown on wastelands is considered as a means to address concerns about climate change and improve energy security while at the same time provide an additional source of income for improving livelihood. The establishment of biomass plantations on wastelands is likely to affect local livelihoods and surrounding ecosystems by influencing hydrologic flows and processes such as erosion. We analyzed the technical feasibility for cultivating Jatropha on degraded waste lands in India using a water balance approach. More specifically, an assessment was made for a wasteland located in the Velchal watershed, Andhra Pradesh, India, which recently was converted to a biofuel plantation with Jatropha. The previous land-use, in this case grazing, could continue in the Jatropha plantations. Several desirable effects occurred as a result of the land-use conversion: non-productive soil evaporation was reduced as a larger share of the precipitation was channeled to productive plant transpiration and groundwater recharge, and at the same time a more stable (less erosive) runoff resulted in reduced soil erosion and improved downstream water conditions. A win-win situation between improved land productivity and soil carbon content was observed for the Jatropha plantations. Results did not show a negative impact on the blue water generation after introducing Jatropha on waste lands. Using parameterized and validated hydrological model “Soil and Water Assessment Tool” we assumed the impact of Jatropha cultivation on 13.4 million ha of wastelands (15% of the total wasteland area) in seven states of India. The analysis shows that 22 million tons of Jatropha seed could be produced from Jatropha cultivable waste lands in India. In addition, Jatropha plantations on waste lands would not create negative impact on downstream water availability and ecosystem services

Conservation agriculture for improving water productivity in Vertisols of semi-arid tropics

Large variability and uncertainty of rainfall are the main limiting factors for crop growth in rainfed agriculture. Agriculture water management interventions are considered as suitable adoption strategy to enhance crop yield, productivity and income in rainfed condition. Three-year experimental data collected at the International Crops Research Institute for the Semi- Arid Tropics, Patancheru, India are analysed to study the impact of in-situ interventions (tillage and crop residue) on field water balance and grain yield under the two different cropping systems (maize + chickpea sequential and maize/pigeon pea intercropping). One dimensional water balance model is calibrated to capture field hydrology (soil water, surface runoff). Weather data calibrated for 36 years showed that incorporating crop residues reduced surface runoff by 28% compared to control fields. However, the impact of tillage and residue treatment on soil water was not consistent throughout the growing period. Water productivity values for intercropping systems (WUE = 0.61 to 1.49 kg m–3) were relatively higher compared to sequential cropping systems (WUE = 0.47 to 1.06 kg m–3). Second crop in sequential cropping system often suffered from water stress that led to poor crop yield. However, a few rain events at the end of the monsoon period were beneficial to second crop. Simulation results indicated that the conservation agriculture could save up to 30% yield loss incurred due to water stress during deficit rainfall compared to conventional agricultural practices

Geomorphic risk maps for river migration using probabilistic modeling – a framework

Lateral migration of meandering rivers poses erosional risks to human settlements, roads, and infrastructure in alluvial floodplains. While there is a large body of scientific literature on the dominant mechanisms driving river migration, it is still not possible to accurately predict river meander evolution over multiple years. This is in part because we do not fully understand the relative contribution of each mechanism and because deterministic mathematical models are not equipped to account for stochasticity in the system. Besides, uncertainty due to model structure deficits and unknown parameter values remains. For a more reliable assessment of risks, we therefore need probabilistic forecasts. Here, we present a workflow to generate geomorphic risk maps for river migration using probabilistic modeling. We start with a simple geometric model for river migration, where nominal migration rates increase with local and upstream curvature. We then account for model structure deficits using smooth random functions. Probabilistic forecasts for river channel position over time are generated by Monte Carlo runs using a distribution of model parameter values inferred from satellite data. We provide a recipe for parameter inference within the Bayesian framework. We demonstrate that such risk maps are relatively more informative in avoiding false negatives, which can be both detrimental and costly, in the context of assessing erosional hazards due to river migration. Our results show that with longer prediction time horizons, the spatial uncertainty of erosional hazard within the entire channel belt increases – with more geographical area falling within 25 % &lt; probability &lt; 75 %. However, forecasts also become more confident about erosion for regions immediately in the vicinity of the river, especially on its cut-bank side. Probabilistic modeling thus allows us to quantify our degree of confidence – which is spatially and temporally variable – in river migration forecasts. We also note that to increase the reliability of these risk maps, we need to describe the first-order dynamics in our model to a reasonable degree of accuracy, and simple geometric models do not always possess such accuracy.</p

A simple and farmer-friendly decision support system for enhancing water use efficiency in agriculture: tool development, testing and validation

In the semi-arid tropics (SAT) farmers practice calendar- based irrigation scheduling, which generally results in over irrigation and poor water use efficiency. The lack of a simple decision tool to decide timing and quantity of water to be applied is a bottleneck. An Excel-based decision support system termed Water Impact Calculator (WIC) is developed using data collected at the ICRISAT, which were validated at three pilot sites on farmers’ fields in Rajasthan, Gujarat and Telangana. Field studies were conducted under two land-form treatments (broad bed and furrow (BBF) and flat fields); and irrigation water was applied following two different methods (drip and flood). The data collected at micro-watershed at the ICRISAT and three other sites showed that WIC could be used under wide range of soil and rainfall conditions. WIC simulated soil moisture was comparable with the observed moisture data, which forms the basis of irrigation scheduling. The WIC-based water balance at these experimental sites showed that number and amount of irrigation could be reduced by 30–40% using WIC-based irrigation scheduling without compromising the crop yield. The WIC could be a potential tool for water resources planning and efficient management at the field and watershed scale in the SAT

Comparative Evaluation of Inductively Coupled Plasma–Optical Emission Spectroscopy and Atomic Absorption Spectrophotometry for Determining DTPA-Extractable Micronutrients in Soils

A study was conducted for comparative evaluation of atomic absorption spectrophotometry (AAS) and inductively coupled plasma–optical emission spectroscopy (ICP-OES) for determining extractable zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) in sixty diverse soil samples having a wide range in pH and organic carbon (C). The results were significantly affected by the method of analysis and soil type but generally did not follow a definite trend. Results for extractable Fe in Alfisol samples were significantly greater when using ICP-OES than AAS; and the results for Zn, Cu, and Mn were not significantly different for the two methods. For Vertisol samples, the results for extractable Cu were significantly greater by ICP-OES than by AAS, whereas extractable Fe and Zn were significantly greater by AAS than by ICP-OES, and the results for Mn were not significantly different for the two methods. The results are discussed relative to soil type and differences in soil organic carbon and pH of the samples used in the study

Association between N2-fixing bacteria and pearl millet plants: responses, mechanisms and persistence

The responses of different cultivars of Pennisetum americanum to inoculation with Azospirillum and Azotobacter spp. with applications of N fertilizer and FYM were studied in 25 experiments at several locations in India. Increased grain yields of >10% (up to 33%) over the non-inoculated controls were observed in 46% of the experiments. In 2 experiments, continued inoculation for 2 or 3 years increased grain, plant biomass yield and N uptake. Application of combined N and FYM tended to increase yield and total plant N uptake. Inoculation did not increase grain N content in any experimen