A field investigation on direct seeded rice (DSR) was carried out in the two consecutive rice growing seasons of 2017 and 2018 at Pantnagar, Uttarakhand, India for the development and validation of soil test crop response (STCR) to fertilizer and for assessing the performance of STCR-treatments as compared to the general recommended dose (GRD) in terms of yield, nutrient uptake and use efficiency, and the economics of DSR. For producing 1 Mg of rice-grain, the required nutrients (N, P, and K) were 2.01 kg, 0.44 kg, and 3.06 kg; the contribution from the soil was 22.05%, 37.34%, and 41.48%; from applied farmyard manure 23.25%, 28.34%, and 16.80%, from fertilizer 38.08%, 49.93%, and 252.98%; and from fertilizer with FYM 44.83%, 60.57%, and 278.70%; for N, P, and K, respectively. The STCR approach, with or without FYM, at both the target yields (4.5 Mg ha⁻¹ and 5.0 Mg ha⁻¹) markedly enhanced the grain yield (20.2% to 32.3%) and production efficiency over the GRD. It also exhibited a higher NPK uptake and use efficiency, along with better profitability, than the GRD. Therefore, the STCR-targeted yield approach could improve the yield, economics, and efficiency of nutrient use for direct seeded rice.

A field experiment was conducted during the pre-kharif season at Uttar Chandamari village in 2012 to study the effects of seaweed saps on growth, yield and quality improvement of green gram in new alluvial soil of West Bengal. The foliar spray was applied twice at different concentrations (0, 2.5, 5.0, 7.5, 10.0 and 15.0% v/v) of seaweed extracts (namely Kappaphycus and Gracilaria). Foliar applications of seaweed extract significantly enhanced the growth, yield and quality parameters. The highest grain yield was recorded with applications of 15% Kappaphykus sap + recommended dose of fertilizer (RDF), followed by 15% Gracilaria - sap + RDF extract resulting in an increase by 38.97 and 33.58% grain yield, respectively compared to the control. The maximum straw yield was also achieved with the application of 15% seaweed extract. Improved crop quality and nutrient uptake [nitrogen (N), phosphorus (P) and potassium (K)] was also observed with seaweed extract applications. Key words: Seaweed saps, Kappaphycus, Gracilaria, recommended dose of fertilizer, green gram.

Increasing productivity of maize while decreasing production costs and maintaining soil health are emerging challenges for the rice–maize system in South Asia. A range of integrated nutrient and weed management practices were tested in winter maize for their effects on yield, profitability, and soil health. The nutrient management treatments were a partial substitution of nitrogen with bulky (Farmyard manure; vermicompost) and concentrated organic manures (Brassicaceous seed meal, BSM; neem cake), whereas weed management practices compared chemical controls only versus an integrated approach. The N supplementation through BSM diminished the weed growth by reducing weed N uptake, and enhanced the maize crop uptake of nutrients. As compared to the sole chemical approach, atrazine-applied pre-emergence followed by hoeing reduced weed density by 58 and 67% in years 1 and 2, respectively. The N supplementation through BSM resulted in the maximum yield of maize grain (6.13 and 6.50 t ha⁻¹ in year 1 and year 2, respectively) and this treatment increased yield in year 2 compared to N application through synthetic fertilizer. Hoeing in conjugation with herbicide enhanced the maize grain yield by 9% over herbicide alone. The maximum net return and economic efficiency were achieved with the application of BSM for N supplementation, together with the integrated weed management practice.

Sustainability and climate change are the two major challenges to the agricultural production system. The trade-off between them is essential for higher profitability. The energy assessment is essential for judging the sustainability and vulnerability of a production system. Besides, nutrient management and weed management are equally imperative to sustainability. Thus, the present study was executed to assess the energy balance, key energy indicators and profitability of rice–maize–green gram system under different nutrient and weed management practices. Application of Brassicaceous seed meal (BSM) along with mineral fertilizer attributed the highest rice (5.62 t ha⁻¹) and maize (6.48 t ha⁻¹) yield which was 11.6%, 8.3% and 3.7% in maize and 10.0%, 6.2% and 8.7% in rice for the conjoint application with vermicompost, farmyard manure (FYM) and neem cake, respectively. Moreover, BSM recorded the highest net energy gain, energy use efficiency and energy efficiency ratio and the lowest specific energy in all the crops. Application of pre-emergence herbicides followed by hoeing was found to be best in all respects including yield, profitability, energy use efficiency, energy effectiveness, etc. The appropriate combination of integrated nutrient management with BSM and pre-emergence herbicide application followed by hoeing provided an additional advantage not only in terms of yield but also an efficient use of energy, profitability and environmental safety. BSM and neem cake could be the alternative organic manure in the integrated nutrient-cum-weed management module and they could be able to compensate the paucity of FYM and vermicompost in the country.