NITROGEN STATUS OF A SALINE SODIC SOIL UNDER CULTIVATION OF AROMATIC CROPS

摘要

Nitrogen deficiency is widespread in saline sodic soils of semi-arid and arid regions of India. Aromatic crops are reported to grow successfully in salt affected soils and their beneficial effect on physicochemical properties of soil. Therefore, a field experiment was conducted during year 2000-2002 to find out the impact of three aromatic crops namely palmarosa (Cymbopogon martinii), lemon grass (Cymbopogon flexuosus) and citronella java (Cymbopogon winterianus) with and without amendments (sludge, hyacinth compost, pyrite) on the status and distribution of nitrogen in a saline sodic soil (pH 8.8, ECe 7.9 dSm~(-1), SAR 35, available N 225 kg·ha~(-1)). Experiment was conducted in a randomized block design with four replications. Cultivation of aromatic crops alone and in combination with organic and inorganic amendments showed steady increase in available N status as compared to initial level. Maximum increase was recorded with the application of hyacinth compost @ 3 t·ha~(-1)+ sludge @ 2 t·ha~(-1) + pyrite @ 40% GR·ha~(-1) (T_6). Among the three crops lemon grass was found superior over palmarosa and citronella java in context of increasing the nitrogen status of soil. In case of lemon grass with T_6 available nitrogen eventually reached 335 kg·ha~(-1) from 225 kg·ha~(-1). It was found that nitrogen in soil at 0 to 15 cm was higher than 15 to 30 cm soil depth. Increased nitrogen status of soil was possible due to addition of organic matter by the residues of aromatic crops and through amendments.