Effect Of Nitrogen Reduction On Growth Of Chinese Cabbage Under Intercropping Of Alfalfa And Chinese Cabbage

The phenomenon of excessive nitrogen application in Chinese cabbage production is widespread,which not only wastes resources,but also leads to soil hardening,low efficiency of soil nutrient use,and other problems.At the same time,it also causes serious nitrate accumulation in Chinese cabbage plants,which is not conducive to human health.Therefore,it is of great significance to it is of great significance to study the reduction of nitrogen fertilization on vegetables for transforming the mode of agricultural development,improve vegetable quality,ensure food safety and increase farmers’ income.As a leguminous forage,alfalfa seedlings can also be eaten as vegetables,and its root system has nitrogen fixation function,which can fix nitrogen in the atmosphere into an effective form of nitrogen that can be absorbed and utilized by plants.Intercropping cultivation provides a better cultivation mode than monoculture cultivation for the future development of modern agriculture with low input and sustainable and stable output in China,and improves the security and nutritional diversity of agricultural output.In China’s agricultural production,leguminous and other crops intercropping is a traditional agricultural mode,which can achieve symbiotic nitrogen fixation between species.Leguminous can effectively fix the air nitrogen of renewable resources.These nitrogen will be used by the same crop through various transfer routes,or be used by non-leguminous crops after cropping through residues.Reasonable legume crop intercropping can also promote the development of legume crop nitrogen fixation advantages,improve the absorption and utilization of nitrogen with legume crop,improve the use of nitrogen fertilizer,and then improve the productivity of unit land area,reduce the input of nitrogen fertilizer,and relatively improve the sustainable production capacity of soil.The agricultural production theme in that 21 st century has always been high yield,good quality and sustainable development,since domestic research on leguminous intercropping is mainly focuses on leguminous and gramineae.However,there are few studies on legumes and vegetables intercropping.This experiment studied the effects of different nitrogen reduction levels,sowing dates and previous crops on the growth of Chinese cabbage under different alfalfa 与 cabbage intercropping patterns,in order to provide a reference for healthy and safe production of Chinese cabbage,and also provide a theoretical basis for reasonable nitrogen fertilizer reduction in Chinese cabbage production.The following conclusions are drawn from the experiments:(1)Intercropping between alfalfa and Chinese cabbage ridge and furrow,to some extent,It also promoted the increase of available phosphorus and potassium content in the soil around the root of Chinese cabbage,and improved soil fertility compared with the farmer’s conventional planting.The nitrate nitrogen,available phosphorus and available potassium content in the soil around the root of Chinese cabbage were increased most obviously by using alfalfa and Chinese cabbage 1: 2 furrow intercropping under the condition of nitrogen reduction of 40%(T2N2).The increase of nitrogen,phosphorus and potassium in soil is beneficial to the growth of Chinese cabbage.The suitable intercropping mode of alfalfa and Chinese cabbage is favorable for yield formation under a certain level of nitrogen fertilizer reduction,Compared with conventional planting,the treatment of 1: 2 furrow-ridge intercropping of alfalfa and Chinese cabbage with 40%nitrogen reduction(T2N2)increased the converted yield by 18.01% and improved the quality(soluble sugar content,soluble protein content,Vc content and chlorophyll content).(2)Early sowing of alfalfa before planting of Chinese cabbage in early spring was beneficial to the accumulation of nitrogen,phosphorus and potassium in soil,the improvement of soil fertility,the growth of Chinese cabbage,the yield of Chinese cabbage and the quality of Chinese cabbage.The treatment with sowing date of April 18(T2B2)was the best.(3)Compared with the previous crops of spring onion,kidney bean and cabbage,alfalfa significantly increased the nitrate nitrogen content,available phosphorus content and available potassium content in the soil after the previous crop.Alfalfa as the previous crop treatment had the best effect on soil improvement.Alfalfa/Chinese cabbage 1: 2 ridge-furrow intercropping was the best way to improve the yield and quality with onion and alfalfa as the previous crop.