Combining Application Of Organic And Inorganic Fertilizer And Straw Mulching On Nitrogen And Phosphorus Runoff Losses In South-central Hilly Tea Garden

Located in southern China’s hilly slope in hunan xingsha town Jin Xiangyuan hui tea factory is one of the main tea area of hunan, as the growing demand for the tea market, tea garden area is expanding, has long been the local tea farmers awareness of environmental protection is weak, tea fanners fertilizer is not science, relies too heavily on chemical fertilizer and using improper fanning methods, production process, the fertilizer utilization ratio is very low. Combined with the regional distribution of tea garden in the slope zone, under the certain condition of rainfall, prone to soil and water conservation and loss of nitrogen and phosphorus and other nutrients, has high nitrogen and phosphorus runoff erosion. Nitrogen and phosphorus pollution load in order to effectively reduce the tea garden, the central hilly tea garden with a slope surface runoff nitrogen and phosphorus nutrient loss characteristics, and puts forward the corresponding prevention and control measures, to improve the tea plantation nutrient use efficiency, reduce the tea plantations of nitrogen and phosphorus nutrient losses, reduce the influence of agricultural non-point source pollution on water environment, and control the eutrophication of lakes and other water bodies is of great importance.The southern hilly in China is tea producing low soil nitrogen content, organic matter, how to reasonable fertilization, improving soil nutrient status, realize regional safe and efficient production and sustainable development, tea and tea plantations of nitrogen and phosphorus runoff erosion prevention and control of lead to environment pollution become a common concern problem.This experiment adopts field plot test, a total of five processing:processing （T1）, said farmers habitually fertilizer （CK）; Processing （T2）, said 10% of chemical N fertilizer, organic fertilizer instead of processing （T3）, said 10% of chemical N fertilizer, organic fertilizer instead of and add straw cover; Processing （T4）,10% organic fertilizer instead of chemical fertilizer P; Processing （T5）,10% organic fertilizer instead of chemical P fertilizer, and add the straw cover.Village tea garden specific fertilizer rate of fertilizer N 442.0 kg K₂O/hm², P2O583.0 kg/hm²,342.0 kg/hm², organic （day spring brand commodity organic fertilizer） according to the content of nitrogen, phosphorus and potassium accordingly reducing the amount of chemical fertilizer, ensure each processing application of nitrogen, phosphorus and potassium fertilizer dosage. Basal in December 2013, in the middle of plowing, fertilizer in early April for the first time into the, the second fertilizer in the summer after the tea picking. Tea garden plot random arrangement, the village tea garden covers an area of 32 m², including two tea in every community. Basal trenching is in the middle of the two tea line of about 20 cm deep plowing, fertilizer is furrowing 5～10 cm deep （broadcasting） of avoid by all means plowing, cover soil immediately after. Community in addition to different fertilizer rate, other management condition and field production, routine management. Test results are as follows:In recent years, in the prevention and control of agricultural non-point source pollution research has been more and more attention both at home and abroad, but its control technology have focused on reducing fertilizer, ecological control, the ditch wetland control, etc., but under the different management approaches, the tea garden the differences of nitrogen and phosphorus runoff erosion and on soil quality, soil fertility and tea tree growth and quality, the influence of environment effect of the research is seldom reported. At present domestic non-point source pollution research is aimed at taihu lake, dianchi lake, such as heavy pollution area, and the non-point source pollution research of south-central hilly region is less. The results are as follows:（1） In south-central hilly tea garden the same rainfall condition, the routine management of surface runoff loss by comparison with the local farmers, under the condition of the same fertilizer treatments, add the processing of straw cover T3 and T5 compared with not adding straw mulching treatment T1, experiments can reduce runoff amount 34.72%-34.91%; And organic inorganic NPK and reduce chemical nitrogen and phosphorus fertilization （T2 and T4）, compared with the conventional application of fertilizer and farmers, can reduce surface runoff amount 2.5%-4.0%; Organic inorganic fertilizer and straw coverage can reduce surface runoff 37.22%-37.22%.（2） In south-central hilly tea garden under the condition of same rainfall conditions and fertilization treatment, compared with farmers used to fertilization, organic and inorganic fertilizer total nitrogen content is reduced by 3.78%～3.85%; Straw covering the total nitrogen content is 24.32%～24.32%; Organic and inorganic fertilizer soluble nitrogen content to reduce 3.52.%～8.99%; Straw covering soluble nitrogen content reduced 20.43. %～24.14%; Organic and inorganic fertilizer ammonium nitrogen content reduced 6.23%～ 6.23%, straw covering ammonium nitrogen content is reduced by 30.89%～32.52%; Organic and inorganic fertilizer nitrate content reduced 0.65%～0.65%, straw covering the nitrate nitrogen content reduced 31.06%～31.06%, nitrogen runoff losses are mainly composed of nitrate nitrogen, ammonium nitrogen.（3）In south-central hilly tea garden under the condition of same rainfall conditions and fertilization treatment, compared with farmers used to fertilization, organic and inorganic fertilizer total phosphorus content is reduced by 0.58%～2.55%, straw covering the total phosphorus content is reduced by 12.88%～12.88%; Organic and inorganic fertilizer soluble phosphorus content to reduce 7.35%～13.17%, straw covering soluble phosphorus content is reduced by 25.02%～31.59%.（4） In south-central hilly tea garden under the condition of same rainfall conditions and fertilization treatment, compared with farmers used to fertilization, organic and inorganic fertilizer of sediment loss reduce 9.10%～9.10%; Straw covering sediment runoff by 43.89%-53.26%. Organic inorganic fertilizer and straw mulching could reduce sediment loss of 52.99-79.76%.（5）Tea demonstration area monitoring area （with a total area of 11541.26 m²） of total surface runoff loss of 424.80 m3, and control area monitoring area （with a total area of 7307.17 m²） of total surface runoff loss of 441.60 m3, conversion to the surface of the total runoff loss per unit area, demonstration area is 368.06 m3/hm², control area 604.33 m3/ hm², demonstration area compared with the control area reduced by 39.1%.（6） Tea demonstration area surface runoff loss of total nitrogen, demonstration area is 0.991 kg/hm², control area is 1.776 kg/hm², the former than the latter decreased by 44.2%; Tea demonstration area surface runoff loss of total phosphorus, demonstration area is 0.224 kg/hm², control area is 0.395 kg/hm², the former 43.3% less than the latter.