Influence of rain water harvesting and conservation practices on growth and biomass production of Azadirachta indica in the Indian desert

A field experiment was conducted to investigate the influence of various rain water harvesting and conservation techniques on soil moisture storage, growth and biomass production of Azadirachta indica (neem) in the Indian desert. The treatments were as follows: control; weed removal; weed removal plus soil working; saucers of 1.0 m diameter; saucers of 1.5 m diameter; saucers of 1.5 m diameter covered with mulch around the trees; bunding around each tree in a checkerboard design; inter-row slopes of 20%. The treatment with inter-row slopes of 20% produced the highest amount of soil moisture storage, a four times increase in total biomass of a 26-month-old neem plantation (from 1.69 to 6.39 t ha⁻¹), a 4.5 times increase in root mass (from 0.43 to 1.92 t ha⁻¹) and a 70% increase in tree height, as well as an appreciable enhancement in all the growth parameters. The treatment with larger saucers (1.5 m diameter) combined with a surface mulch was equally effective. Growth increases owing to the other water harvesting treatments were lower, though significantly better when compared with the control. The various treatments significantly improved the water use efficiency of neem.