Integrated organic nutrient management: a sustainable approach for cleaner maize (Zea mays L.) production in the Indian Himalayas.

Inadequate availability of quality organic nutrient sources is the major hurdle in adopting organic farming. Hence, a study was conducted during 2019–21 at Sikkim state of the Indian Himalayas to investigate the effect of integrated organic manuring on energy dynamics, profitability, and soil health of maize (Zea mays L.) crops grown in acidic soil. Five organic nutrient management practices viz., T2: 100% recommended dose of nitrogen (RDN) through farmyard manure (FYM); T3: 100% RDN through mixed compost (MC); T4: 100% RDN through vermicompost (VC); T5: 50% RDN through FYM and 50% RDN through MC + biofertilizers (BFs) and T6: 50% RDN through FYM and 50% RDN through VC + BFs were tested in a four-times replicated randomized block design against the farmers' practice (T1: application of 5 Mg ha⁻¹ FYM). Results indicated that the supply of 50% RDN through FYM and 50% RDN through MC along with the BFs consortium improved the green cob and biological yields, net return, production efficiency, energy net return, and energy output efficiency by 26.3%, 24.8%, 29%, 26.4%, 24%, and 24.7%, respectively over farmers' practices. Likewise, the supply of 50% RDN through FYM + 50% RDN through MC + BFs reduced soil bulk density (pb) by 6.87% while increasing total water stable aggregates (TWSA) by 23.1% and mean weight diameter (MWD) by 18.7% over farmers' practice. Similarly, a significant improvement in soil organic carbon, available N, P, K, Zn, Fe, and Mn was observed with 50% RDN through FYM + 50% RDN through MC + BFs over farmmers' practice. Furthermore, integrated nitrogen supply with FYM and MC in equal proportion improved soil enzymatic activity considerably over existing practice. Hence, the study inferred that the supply of 50% RDN through FYM + 50% RDN through MC + BFs may be a viable and soil-supportive approach for cleaner maize production in the acidic soils of Indian Himalayas and other similar ecoregions. [ABSTRACT FROM AUTHOR]