论文部分内容阅读
Ten rainfall and irrigation water-collecting posts were set up in different ecotype districts of JiangxiProvince, China, to quarterly measure S content in rainfall and irrigation water. A rainwater chemicalcomposition- collecting device was used to collect the sulphur in rainfall land the amount of sulphur adsorbedon the resin column in the device was determined. The soil percolating water was gathered using 6 lysimeters,built up according to the profile sequence of the red soil derived from red sandstone and the red soil derivedfrom Quaternary red clay, separately. On the lysimeters peanuts, soybean and radish were grown in rotation.Two treatments were designed: without S addition and with S addition at a rate of 14 kg S ha-1. The SO24contents in rainfall, irrigation water and soil percolating water were determined by the turbidimetry.The results in 1997 showed that the average annual S content in rainwater was 28.13 kg S ha-1, theaverage S content in irrigation water was 1.7 mg S L-1 , and the average content of in soil percolationwater was 2.30 kg S ha-1 year-1 and 4.70 kg S ha-l year-1 in treatments without and with sulphurapplication, respectively. In Jiangxi Province, apart from the losses by runoff and leaching, the sulphur inrainfall available to crops is 7.3 kg S ha-1 year-1 and additional S application is required. When rice isgrown , however, irrigation water can supply 6.9 kg S ha-1, which, along with the sulphur in rainfall, canalmost meet the S requirement of one cropping of rice.
Ten rainfall and irrigation water-collecting posts were set up in different ecotype districts of Jiangxi Province, China, to quarterly measure S content in rainfall and irrigation water. A rainwater chemicalcomposition- collecting device was used to collect the sulphur in rainfall land the amount of sulfur adsorbedon the resin column in the device was determined. The soil percolating water was gathered using 6 lysimeters, built up according to the profile sequence of the red soil derived from red sandstone and the red soil derivedfrom Quaternary red clay, separately. On the lysimeters peanuts , soybean and radish were grown in rotation. Two treatments were designed: without S addition and with S addition at a rate of 14 kg S ha-1. The SO24contents in rainfall, irrigation water and soil percolating water were determined by the turbidimetry. results in 1997 showed that the average annual S content in rainwater was 28.13 kg S ha-1, theaverage S content in irrigation water was 1.7 mg S L-1 , and the average content of in percolation water was 2.30 kg S ha-1 year-1 and 4.70 kg S ha-l year-1 in treatments without and with sulphurapplication, respectively. In Jiangxi Province, apart from the losses by runoff and leaching , the sulphur inrainfall available to crops is 7.3 kg S ha-1 year-1 and additional S application is required. When rice is grown, however, irrigation water can supply 6.9 kg S ha-1, which, along with the sulfur in rainfall, canalmost meet the S requirement of one cropping of rice.