Early tree growth and crop yields under Prosopis cineraria and Ailanthus excelsa based agroforestry system in north western India

Abstract

A field experiment was initiated in 2017 to evaluate the effect of tree species and tree spacing on intercropproductivity and tree growth with advancing age of Prosopis cineraria and Ailanthus excelsa in an agroforestrysystem at Bikaner, Rajasthan. Both P. cineraria and A. excelsa were planted at three spacings: 4m × 4m, 6m ×6m and 8m × 8m; and Cyamopsis tetragonoloba L. Taub. (Cluster bean) was grown as intercrop during thekharif seasons of 2018 and 2019. At 24 months after planting (MAP), A. excelsa trees were significantly tallerand thicker in wider spacings of 6m × 6m and 8m × 8m compared to closer spacing of 4m × 4m; while in P.cineraria, different spacings did not significantly affect tree height and collar diameter. In this period, collardiameter and height of A. excelsa increased by 10.9 and 6.9-fold in 6m × 6m and 9.9 and 6.8-fold in 8m × 8mspacing, respectively. Percent increment in tree growth parameters were higher during initial growth period (612 MAP), and decreased in the subsequent months for both A. excelsa and P. cineraria. Among the differentspacings, higher percent increment in collar diameter in both the species at 24 MAP was recorded in 6m × 6mspacing. The intercrop yield in both the years was not significantly affected by different tree species andspacings. The study indicated that A. excelsa could be established and grown faster in arid region at widerspacings to get maximum tree growth.