Enhanced nutrient and rainwater use efficiency in maize and soybean with secondary and micronutrient amendments in the rainfed semi-arid tropics

Abstract

In view of widespread deficiencies, a long-term experiment was started at the International Crops Research Institute for the Semi-Arid Tropics, Patancheru, India in 2007 to identify economically efficient application strategy (full or 50% dose every or every second year) of sulphur (S) (30 kg ha⁻¹), boron (B) (0.5 kg ha⁻¹) and zinc (Zn) (10 kg ha⁻¹). During the fourth year in 2010, balanced fertilization through adding S, B and Zn increased maize grain yield by 13–52% and soybean yield by 16–28% compared to nitrogen (N) and phosphorus (P) fertilization alone. Balanced nutrition increased N and P uptake, utilization and use efficiency for grain yield and harvest index indicating improved grain nutritional quality. The N, P plus 50% of S, B and Zn application every year recorded highest crop yields and N and P efficiencies indices and increased rainwater use efficiency with a benefit:cost ratio of 11.9 for maize and 4.14 for soybean. This study showed the importance of a deficient secondary nutrient S and micronutrients B, Zn in improving N and P use efficiency while enhancing economic food production.

Keywords:

• micronutrients deficiency
• N use efficiency
• nutrient uptake
• P use efficiency
• rainfed agriculture
• rainwater use efficiency

Acknowledgements

The authors gratefully acknowledge the help from Mr P Narsimha Rao in field experimentation. The help from Mr G Pardhasaradhi, Ms K Shirisha and Mr C Vijaya Ranganatha in analysing plant samples and from Dr Abhishek Rathore, Mr Ravikumar Dasari and Ms Roma Das from Biometrics Unit in statistically analysing the data is also acknowledged.