LONG-TERM EXPERIMENTS ON THE EFFECT OF RICE STRAW ADDITION ON SOIL PROPERTIES an‎d CROP PRODUCTIVITY

Long-term experiment was carried out during the fall growing season in nineteen successive seasons. The experimental area with and without rice straw was tilled by using the conservation tillage system (one pass chiseling followed by rotary tiller). The experimental area was planted with wheat followed by rice crop during the whole experiments. The obtained results indicated that the addition of rice straw, leading to lower soil penetration resistance during the growing season about 5.6, 5.9, 2.2 and 1.1% in comparison with the treatment without rice straw at depths of 5, 10, 15 and 20 cm, respectively. The crop yield increased about 28 and 23.4% more than the rice and wheat crop yields at treatment without rice straw, respectively.