Effect of short-rotation trees on nutrient dynamics and rooting pattern in intercropped with aromatic grasses in terai of U.P.

An Experiment was conducted in District Pilibhit.U.P., to study the yields of aromatic grasses in pure fields as well as intercrops under Populus deltoids and Eucalyptus hybrid. Quantity of litterfall, its chemical composition, nutrient addition, changes in chemical constituents of soil and herb and oil yield of Cymbopogon spp. were studied under agroforestry systems involving Populus deltoids and Eucalyptus hybrid with intercrop of Aromatic grasses (C.winterianus, C.martinii, C.flexouses). Trees were intercropped with grasses have significantly more diameter and height in comparison to trees planted without intercrops. High herbage and oil yield was recorded in pure fields of grasses than their crops intercropped with trees. Maximum yield was produced by Palmarosa and minimum by Citronella in poplar plantation intercropped. In Eucalyptus hybrid intercropped grasses, maximum oil yield was produced by Lemon grass and minimum by Palmarosa. Higher quantity of litter was produced in Palmarosa and lower was produced in Citronella intercropped trees. The litter produced by the intercropped stands had higher NPK contents than pure stands. The concentration of nutrients in the litter decreased with increasing age of the stands. Similarly, the total addition of nutrients (NPK) through litter fall to the soil increased as the age of trees increased. In the field of trees intercropped with Palmarosa was maximum addition of nutrients, while in Citronella intercropped field it was seen minimum. In comparison to intercropped stands, available NPK content of soil was higher in pure stands of trees. Maximum amount of N and K was found in superficial layer of the soil, which decreased with increasing depth. Most of the phosphorus was accumulated in the soil at the depth of 15-30cm in all the stands. The concentration of roots was more near the base of the trees at juvenile age,but as the age increases the roots tended to proliferates uniformly.. The total root biomass decreased continuously with increasing soil depth at all the radial distances and under all the age groups. It is clear that there is no completion among the root system with roots of intercrops grown along with Poplar and Eucalyptus.