Recent Trends in Inter-Relationship of Nutrients with Various Agronomic Practices of Field Crops in India.

The spectacular performance of Indian agriculture witnessed during the second half of the 20th century against the onslaught of rising demographic pressure is a vivid demonstration of the growing effectiveness of our agricultural research and development system. However, the issue of sustainability in agriculture still remains a question. Management of natural resources, especially soil and its fertility status and vegetation following suitable agronomic management practices for sustainable agricultural production, represents a most daunting task and is certainly going to receive much attention in the years to come. Many workers established functional relationships between nutrients and other agronomic factors at different locations in India but systematic compilation of those relationships is a rare effort. The present paper reviews the latest information on inter-relationships between nutrients and other agronomic factors (seed rate, planting density, age of the seedling, planting method, irrigation, weed control, tillage, bacterial inoculation and cultivar etc.) on field crops. Major findings of first and second order interactions are highlighted. None of the second order interaction was found significant; thus only first order interactions were discussed. The interactive effect of nutrients and seed rate varied with soil type. In sandy loam soil when 125 kg seed ha[sup -1] was used, wheat responded up to 60:30:40 kg N, P[sub 2]O[sub 5] and K[sub 2]O ha[sup -1], whereas in clay loam soil it was up to 80:40:30 kg N, P[sub 2]O[sub 5] and K[sub 2]O ha[sup -1] with the use of 25 kg higher seed rate. When chickpea was grown with a medium seed rate of 75 kg ha[sup -1] it responded up to 30 kg N and 60 kg P[sub 2]O[sub 5] ha[sup -1] saving 10 kg N and 20 kg P[sub 2]O[sub 5] in comparison to when a higher seed rate of 100 kg was used. Younger seedlings (20-25 days) performed better than old seedlings (35-40 days) in timely sown rice with the recommended dose of N,... [ABSTRACT FROM AUTHOR]