Effect Of Grass Stubble Returned To Soil On The Paddy Soil Nutrient Under The Condition Of Simulated Acid Rain

The south of China has been listed as one of the three major acid rain areas in the world, and the soil acidification is seriously here, and there is a trend of further expansion.Acid rain can reduce the pH of soil, lead to poor soil, influence soil nutrient conversion, and ultimately to reduce productivity, and will seriously hinder the sustainable development of agriculture. The straw returned to soil can improve of soil quality, supplement soil organic matter and other nutrient, alleviate soil nutrient leaching caused by acid rain, with improving soil fertility and crop yield effect.However, the effect of different varieties of grass stubble returned to soil under the condition of acid rain leaching, the effect of different nutrient forms of soil on the mitigation of the effects of the study is also rare. Therefore, to investigate the change rule of carbon, nitrogen, phosphorus and soil enzyme activities in the paddy soil under the condition of simulated acid rain, this study selected the paddy soil as the test soil, and simulated acid rain leaching test. The six soecies of cool-season season grass stubble were Ryegrass, Alopecurus, Oat grass, White clover, Chinese milk-vetch and Rape. The main results are as follows:1.Grass stubble returned to soil can relieve the leaching of simulated acid rain on carbon element in paddy soil.The best effect to alleviate the organic matter leaching is Alopecurus grass stubble, following by Chinese milk-vetch stubble, White Clove stubble,Rape stubble and Oat grass stubble, Ryegrass stubble is the worst.The best effect to alleviate the active organic carbon leaching is White Clove stubble,followed by Rape stubble,Oat grass stubble,Ryegrass stubble and Chinese milk-vetch grass stubble, Alopecurus stubble is the worst.2.Grass stubble returned to soil can relieve the leaching of simulated acid rain on nitrogen element in paddy soil.The best effect to alleviate the total nitrogen leaching is Alopecurusgrass stubble.following by Chinese milk-vetch stubble,White Clove stubble,Rape stubble and Oat grassstubble,Ryegrass stubble is the worst. The best effect to alleviate the available nitrogen leaching is Alopecurus stubble,followed by Oat grass stubble,Ryegrass stubble.Rape stubble and Chinese milk-vetchstubble. White Clove stubble is the worst.3.Grass stubble returned to soil can relieve the leaching of simulated acid rain on phosphorus element in paddy soil.The best effect to alleviate the total phosphorus leaching is Rape grass stubble,following by White Clove stubble,Chinese milk-vetch stubble,Alopecurus stubble and Ryegrass stubble,Oat grass stubble is the worst.The best effect to alleviate the available phosphorus leaching is Rape stubble,followed by White Clove stubble,Chinese milk-vetch stubble,Alopecurus stubble and Ryegrass stubble,Oat grass stubble is the worst.4.Grass stubble returned to soil can relieve the damage of simulated acid rain on the activity of enzymes in paddy soil.The best effect to alleviate the damage to activity of protease is Rape stubble, following by Ryegrass stubble,Chinese milk-vetch stubble,White Clove stubble and Alopecurus stubble,Oat grass stubble is the worst.The best effect to alleviate the damage to activity of acid phosphatase is White Clovestubble, following by Chinese milk-vetch stubble,Ryegrass stubble,Alopecurus stubble and Rape stubble,Oat grass stubble is the worst.The best effect to alleviate the damage to activity of Catalase is White Clove stubble,following by Rape stubble,Oat grass stubble,Alopecurus stubble and Ryegrass stubble,Chinese milk-vetch stubble is the worst.The best effect to alleviate the damage to activity of urease is Rape stubble,following by White Clove stubble,Ryegrass stubble,Chinese milk-vetch stubble and Alopecurus stubble,Oat grass stubble is the worst.