EFFECT OF IRRIGATION AND NUTRIENT REGIMES ON MOISTURE DISTRIBUTION PATTERN AND AVAILABLE NUTRIENTS UNDER YOUNG CHIR PINE (PINUS ROXBURGHII) PLANTATION IN MID HILL CONDITIONS OF HIMACHAL PRADESH

摘要

A field experiment was conducted during May 2001 to May 2002 to study the effect of irrigation and nutrient regimes on soil moisture status, availability of nutrients and biomass in under young Chir pine (Pinus roxburghii) plantation. Nine treatmentcombinations comprising of three irrigation regimes and three nutrient regimes were tested. The study revealed that the higher irrigation (IR_2) and nutrient (NR_2) regimes and their interaction (IR_2NR_2) significantly increased the availability of N,Pand K over control (IR_0 NR_0 ). The availability of N, P and K decreased by 12.4-16.0, 4.07-5.18 and 12.5-14.0 kg/ha, respectively in 0-15 cm depth during a period of six months and also decreased with depth. The plantation under dry irrigation regime(IR_0) encountered severe moisture stress during September to January and March to May and growth was adversely affected. The higher irrigation (IR_2) and nutrient (NR_2) regimes and their positive interaction (IR_2NR_2) effect registered 21.87, 24.77 and 48.10 per cent higher above ground biomass over control.