Summer green-manuring crops and zinc fertilization on productivity and economics of basmati rice (Oryza sativa L.)

Abstract

Field experiments were conducted to study the effects of summer green-manuring crops and zinc (Zn) fertilization on the productivity and economics of Basmati rice. Sesbania aculeata summer green-manuring crop residue incorporation (SGMI) gave highest values of all the growth and yield attributes, grain and straw yield, viz. 3.58, 3.69 t ha⁻¹ and 16.14, 16.25 t ha⁻¹ of Basmati rice in 2008 and 2009. Among the Zn fertilization treatments, application of 2.0% Zn-enriched urea (ZEU) as ZnSO₄ · H₂O significantly influenced yield attributes and yield of Basmati rice during both years, and the increase in grain yield was 38.5 and 40.0% over absolute control (no N and no Zn) and 11.9 and 13.6% over control (only N) in both years of study. However, 2.0% ZEU (ZnO) was very close in terms of yield attributes and grain, straw yields of Basmati rice. As regards to the economics of Basmati rice, SGMI and 2.0% ZEU (ZnSO₄ · H₂O) Zn fertilization treatments gave the highest gross (SGMI, 85,985 and 91,582 INR ha⁻¹; 2.0% ZEU, 89,837 and 59,851 INR ha⁻¹) and net (SGMI, 56,997 and 61,445 INR ha⁻¹; 2.0% ZEU, 59,851 and 64,442 INR ha⁻¹) returns, respectively, compared with incorporation of the remaining summer green manuring residue and Zn fertilization treatments in 2008 and 2009. A significantly higher benefit:cost ratio was recorded with SGMI and 2.0% ZEU (ZnSO₄ · H₂O). Overall, Sesbania aculeata green manuring and 2.0% ZEU (ZnSO₄ · H₂O) are excellent sources of N and Zn for improved productivity of Basmati rice.

Keywords:

• Basmati rice
• economics
• summer green-manuring crops
• yield
• Zn-enriched urea
• Zn fertilization

Acknowledgements

The senior author gratefully acknowledges the assistance received in the form of Senior Research Fellowship from the Director, Indian Agricultural Research Institute, New Delhi, during his Doctor of Philosophy degree programme. Thanks are also due to the Head of Division of Agronomy for providing the necessary field and laboratory facilities during the course of the investigation.