Growth, production and resource use in Colophospermum mopane-based agroforestry system in north-western India

Abstract

Two-year-old Colophospermum mopane (Kirk et Benth) Kirk ex J. Leonard plants were intercropped for 7 years with a view to study the effect of tree integration and cropping pattern on land productivity. Tree-integrated plots were C. mopane with Vigna radiata (FC) and with rotation crop (RC), whereas control plots were sole V. radiata (CFC), and sole rotation crop (CRC). Pennisetum glaucum (L.) R.Br., V. radiata, Sesamum indicum and Cymopsis tetragonoloba were harvested in the RC/CRC plots. Tree growth variables, biomass and system productivity (tree + crop) did not differ between FC and RC plots. Mean annual increment in tree biomass was 1.2 tonnes ha⁻¹ year⁻¹. The highest (p < 0.01) grain and dry matter yield in tree-integrated plots from 1996 – 2000, and in the control plots in 2001 and 2003 indicated a shift from facilitation to competition with tree age. Tree-integrated plots had 2 – 36% less (p < 0.05) soil water than in the control indicating tree water use. Added litters and nutrient uptake by tree increased soil organic matter and decreased available PO₄[sbnd]P, NH₄[sbnd]N and NO₃[sbnd]N in the tree-integrated plots. Conclusively, C. mopane enhances land productivity through increased system production and agriculture yield in the initial 4 – 5 years. It can be made beneficial by canopy restructuring and root trenching to reduce competition for the resources at higher age.

Keywords:

• Crop yield
• tree growth
• tree biomass
• soil water
• soil nutrients
• system productivity

Acknowledgements

Authors are thankful to the Director, Arid Forest Research Institute for providing the necessary facilities to carry out this experiment.