Kuntal M. Hati

Bioenergy and economic analysis of soybean-based crop production systems in central India

The study examines the energy requirement and energy input–output relationship of soybean-based crop production systems viz., soybean (Glycine max (L.) Merr.)–wheat (Triticum aestivum L.), soybean–mustard (Brassica juncea (L.) Czern & Coss.) and soybean–chickpea (Cicer arietinum L.) in central India. Using a pre-tested questionnaire, 135 farmers were selected through a multi-stage stratified random sampling technique. Results revealed that manures and chemical fertilizers (50.87%), seedbed preparation (18.30%) and sowing management (17.69%) consumed the bulk of the energy (operational and non-operational) for all crops, it was highest in soybean–wheat and the lowest in soybean–chickpea . Wheat, with the highest grain productivity, produced the most biomass energy and highest grain-energy productivity . The total bioenergy output of the crop production systems followed the order: soybean–wheat soybean–mustard soybean–chickpea . But this order was reversed for energy-use efficiency (EUE): soybean–chickpea (5.91)> soybean–mustard (5.86)> soybean–wheat (5.54). Specific energy was highest in soybean grain) followed by mustard seed), chickpea grain) and wheat grain) indicating that soybean is the most energy-investment intensive crop. Regarding energy intensiveness the results were contrary to EUE. Energy intensiveness was higher in wheat (1.40) followed by mustard (1.11), soybean (0.89) and chickpea (0.87) and the soybean–wheat system (1.13) emerged as the most energy-intensive system compared to soybean–mustard (0.97) and soybean–chickpea (0.88). Though the net return from soybean–wheat was marginally higher than other systems, the soybean–chickpea system is more suitable in the central ecological niche of India due to its low requirement for non-renewable resources, higher EUE and benefit–cost ratio.

Long-term continuous cropping, fertilisation, and manuring effects on physical properties and organic carbon content of a sandy loam soil

Effects of continuous cropping, fertilisation, and manuring on soil organic carbon content and physical properties such as particle size distribution, bulk density, aggregation, porosity, and water retention characteristics of a Typic Ustochrept were examined after 31 cycles of maize–wheat–cowpea (fodder) crop rotation. Five contrasting nutrient treatments from a long-term fertiliser experiment were chosen for this study: control (no fertiliser or manure); 100% (optimum dose) nitrogen (N) fertiliser; 100% nitrogen and phosphorus (NP); 100% nitrogen, phosphorus, and potassium (NPK); 100% NPK + farmyard manure (NPK+FYM). The NPK+FYM treatment significantly improved soil organic carbon (SOC) content in 0–0.15 m soil compared with the other 4 treatments; the NPK treatment resulted in significantly more SOC than the control and N treatments (P < 0.05). The SOC in NPK and NPK+FYM treatments was 38.6 and 63.6%, respectively, more than the initial level of SOC (4.4 g/kg) after 31 cycles of cropping. The control and N treatments maintained the SOC status of the soil at the initial value. NPK+FYM significantly improved soil aggregation, soil water retention, microporosity, and available water capacity and reduced bulk density of the soil at 0–0.30 m depth. Greater crop growth under the NPK treatment resulted in increased organic matter content of soil, which improved aggregate stability, water retention capacity, and microporosity compared with the control. The effects were more conspicuous with the NPK+FYM treatment and at the surface soil (0–0.15 m). Application of imbalanced inorganic fertiliser (N and NP treatments) did not have a deleterious effect on the physical properties of the soil compared with the control. SOC content showed a highly significant and positive correlation with mean weight diameter (0.60), % water-stable macro-aggregates (0.61), and soil water retention at –0.033 MPa (0.75) and –1.5 MPa (0.72), and negative correlation with bulk density (–0.70) for the surface 0–0.15 m soil. The study thus suggests that application of balanced mineral fertilisers in combination with organic manure sustains a better soil physical environment and higher crop productivity under intensive cultivation.

Cropping Systems of Central India: An Energy and Economic Analysis

ABSTRACT The study attempts to analyze the energy input-output relationship and economic returns of the cropping systems in central India. The data collected from farmers through multistage random sampling techniques, were subjected to descriptive analysis of simple proportions and percentages. Findings reveal that total energy involved in soybean-wheat system (19817 MJ ha−1; renewable 5507 MJ ha−1 and non-renewable 14310 MJ ha−1) is much greater than soybean-chickpea (11239 MJ ha−1; renewable 4883 MJ ha−1 and non-renewable 6356 MJ ha−1), pigeonpea monocropping (2329 MJ ha−1; renewable 714 MJ ha−1 and non-renewable 1616 MJ ha−1), fallow-wheat (13716 MJ ha−1; renewable 2810 MJ ha−1 and non-renewable 10906 MJ ha−1) and fallow-chickpea (4445 MJ ha−1; renewable 2526 MJ ha−1 and non-renewable 1919 MJ ha−1). The percentage of non-renewable energy is higher than renewable energy inputs. Soybean-wheat (70%) and fallow-wheat (78%) systems resorted to more use of non-renewable energy than renewable energy. In soybean-chickpea system share of non-renewable energy is 52%. The energy outputs follow the order: soybean-wheat (70495 MJ ha−1) > fallow-wheat (52084 MJ ha−1) > soybean-chickpea (44485 MJ ha−1) > pigeonpea monocropping (20427 MJ ha−1) > fallow-chickpea (20357 MJ ha−1); energy efficiency is the highest in pigeonpea mono-cropping (8.76); for other systems it ranged from 3.67 in soybean-wheat to 4.63 in fallow-chickpea system. The net energy of the systems is 50678 MJ ha−1 in soybean-wheat, 38368 MJ ha−1 in fallow-wheat, 33246 MJ ha−1 in soybean-chickpea, 18098 MJ ha−1 in pigeonpea monocropping and 15912 MJ ha−1 in fallow-chickpea. Though the soybean-wheat system results in highest net energy, its energy productivity (0.269 kg MJ−1) is the lowest and that of fallow-wheat system is 0.288 kg MJ−1. It is comparatively higher for other systems, viz., soybean-chickpea (0.307 kg MJ−1), pigeonpea monocropping (0.643 kg MJ−1) and fallow-chickpea (0.342 kg MJ−1). Further, energy intensity is 3.84 MJ kg−1 and 0.887 MJ Rs.−1 in physical and economic terms, respectively, in the soybean-wheat system, and are greater than other systems, viz., soybean-chickpea (3.43 MJ kg−1 and 0.577 MJ Rs.−1), pigeonpea monocropping (1.55 MJ kg−1 and 0.243 MJ Rs.−1), fallow-wheat (3.59 MJ kg−1 and 1.408 MJ Rs.−1) and fallow-chickpea (2.96 MJ kg−1 and 0.569 MJ Rs.−1). But the soybean-wheat cropping system has been found more remunerative in terms of benefit-cost ratio (1.27) owing to its ability to generate the highest return per rupee investment than soybean-chickpea (1.23) and pigeonpea monocropping (1.23). The fallow-based systems are having comparatively better benefit/cost ratio. The investment requirement and also net return is highest for soybean-wheat system, thus is preferred by the large farmers. Farmers are forced to use soybean-chickpea crop rotation whenever there is lack of adequate rainfall during rainy season and irrigation facilities in succeeding winter season. Thus, fallow-chickpea rotation is suitable for extremely poor farmers with no irrigation facilities.

The response of weed community in soybean with conventional and conservation tillage systems on rainfed Vertisols

A change in tillage system from conventional to conservation tillage may influence weed population, diversity and weed seed distribution in the soil profile. Therefore, a field study was conducted during 2009 through 2011 to investigate the effects of tillage system. The number of grassy weeds was least in the no-tillage (NT), reduced till (RT) and mould board plough (MB) treatments compared to the conventional till (CT) treatment. More dicot weeds were recorded in the RT and NT plots than the CT. Averaged over seasons, the CT and MB treatments had 17–30% more weed species than RT and NT treatments. Treatments NT, RT and CT had more weed seeds in 0–5 cm soil depth than the MB. The trend in 5–15 cm soil depth was MB > CT > RT = NT. Tillage systems had significant effect on soybean seed yield in one of the 3 years. Averaged over years, the CT treatment had the lowest seed yield (458 kg ha−1), significantly lower than the MB and RT treatments (522–550 kg ha−1). Seed yields were lower with one (452 kg ha−1) than two (566 kg ha−1) weeding operations. Our results indicate conservation till systems as a suitable option for soybean grown on Vertisols.