Kapila Shekhawat

Residual effects of nitrogen sources, sulfur and boron levels on mungbean (Vigna radiata) in a sunflower (Helianthus annuus)–mungbean system

Field experiments were conducted during spring–rainy (kharif) seasons of 2005 and 2006 on a sunflower–mungbean cropping system at the research farm of the Division of Agronomy, Indian Agricultural Research Institute (IARI), New Delhi, India. The objectives of this study were to investigate the residual effect of nitrogen sources, sulfur and boron levels applied to sunflower on productivity, nutrient concentrations and their uptake by the succeeding mungbean crop in a sunflower–mungbean cropping system. The experiment with 19 treatments was laid out in factorial randomized block design for both sunflower and mungbean. The residual effects of nutrients applied to sunflower were significant on the succeeding mungbean crop in terms of biometric parameters, yield attributing characters, seed yield and soil nutrient status. The highest mungbean seed yield (961.2 kg ha−1) was produced with 50 kg ha−1 sulfur application to the preceding sunflower crop, which was significantly (p < 0.05) higher than with 0 and 25 kg sulfur ha−1. The concentrations and uptake of nitrogen, sulfur and boron were also greater in the succeeding mungbean crop due to the residual effects of nutrients applied to the preceding sunflower crop. The soil nutrient status before and after mungbean indicated that the available nitrogen and sulfur were higher due to application to the preceding crop, while available boron after mungbean was even higher than after sunflower due to its slow release and static nature in the soil.

Phytoremediation Mechanism in Indian Mustard ( Brassica juncea ) and Its Enhancement Through Agronomic Interventions

The increasing heavy metal pollution in the agro-ecosystem has become a serious concern worldwide. These metals do not decay in the nature and become toxic to the plants, animals and human beings when exceed specific thresholds. Anthropogenic input of heavy metals in agricultural land includes industrial and agricultural disposal, waste incineration and urban effluent of wastewater. Phytoremediation, by using metal-accumulating plants like Brassica sp., including Indian mustard (Brassica juncea) for toxic metal removal from soil has been proposed as a possible solution to this problem. Phytoremediation is a cost effective and nondestructive, but the challenges in the fast extraction of heavy metals by Indian mustard include initial slow growth, ability to extract some particular metal only, poor bioavailability of heavy metals in soils and non-compartmentalization within plant parts. Addition of organic matter, organic chelates, soil amendments, adoption of suitable cropping systems, intercrops and fertilizer selection can enhance the phytoremediation capacity of Indian mustard. Growing Indian mustard with these agronomic interventions can augment the ability to absorb, uptake and concentrate heavy metal under contaminating soils.

Sustaining higher mustard productivity through conservation agriculture in semi-arid regions of India

The field experiments were conducted at Directorate of Rapeseed-Mustard Research (DRMR), Bharatpur, India to evaluate the effect of crop establishment methods on crop productivity, soil properties and economics of mustard in a cropping system mode. Conventional tillage (CT), reduced tillage (RT), zero tillage (ZT) and permanent furrow irrigated raised beds (FIRB) were tested for five mustard-based cropping systems viz., fallow-mustard, green manure-mustard, brown manure-mustard, clusterbean-mustard and pearl millet-mustard in split-plot design replicated thrice. The seed, stover, total biological yields, sustainability indices and economics of mustard were significantly influenced by various crop establishment methods and cropping systems. Soil carbon footprints and bulk density of semi-arid regions improved under conservation agriculture. The average increase in the seed yield of mustard after four years of the experimentation was 32.4 and 20.7%, respectively, under FIRB and ZT. The highest sustainability yield index (0.85) and production efficiency (16.01 kg/ha/day) were also observed under FIRB. An increase of 1.30 g/kg and 2.57 Mg/ha in soil organic carbon and mass of soil organic carbon, respectively, was recorded in ZT over CT. The highest mustard yield was obtained under green manure-mustard cropping system (2549 kg/ha) followed by clusterbean-mustard system (2348 kg/ha). The net returns, profitability and B: C ratio were recorded highest with FIRB and green manure-mustard cropping systems.