Effects Of Water And Nitrogen Coupling On Nutrient Absorption And Growth Of Peanut

In the cultivation and management for quality and high yield peanut,water and nitrogen fertilizer are decisive in the production of peanut.At present,there still exist some problems in Chinese peanut production area such as low utilization efficiency of water and fertilizer,unreasonable use of resources and so on.Therefore,it is of great practical significance to study the effects of water and nitrogen on peanut to improve the utilization efficiency of water and nitrogen and realize the high yield of peanut,so as to get the optimal water and nitrogen coupling mode for peanut production with high yield and high efficiency.In this experiment,peanut "Huayu 25" and "Xiaobaisha" as the experimental material,using two factor randomized block design,through canopy field experiment and laboratory analysis of water and nitrogen coupling effect on peanut growth,physiological characteristics,nutrient uptake and supply.It is expected to provide theoretical basis for high yield and quality water and fertilizer management technology of peanut in arid and semi-arid area.The main findings are as follows:(1)Compared with the initial soil nutrients in 2013,the content of soil total nitrogen and soil available nitrogen increased,and the content of soil available nitrogen increased significantly with the increase of nitrogen application rate,while the content of available phosphorus in soil decreased,but the content of available potassium in soil was increased,and the others decreased.The total nitrogen content of peanut plants was only affected by the amount of nitrogen fertilizer,while increasing nitrogen application rate could increase nitrogen content of peanut plant.The total phosphorus and total potassium content of peanut plants were significantly affected by water and nitrogen coupling.N1W2 treatment could effectively improve the nitrogen use efficiency of peanut.(2)Irrigation plays a decisive role in the growth and development of peanut,and the effects on root system,root activity and biomass are significant or extremely significant.Effect of water and nitrogen coupling on the growth and development of peanut root had significant effect on nitrogen,N1(15kg N hm"2)or irrigation W2(2810 m3 hm-2)conditions,to peanut root length,root diameter and root volume reached the maximum.The treatment of W2N1 could promote the root system of peanut,which was beneficial to the increase of root biomass.In the stage of peanut pod,nitrogen can improve the root activity,and provide the basis for high yield of peanut.In addition to mature period,the peanut development increase of nitrogen was beneficial to promoting the activity of root vigor.The effect of same nitrogen fertilizer on the growth of peanut was inhibited,and the stem height and stem diameter increased with the increase of irrigation amount.The maximum yield of peanut in two seasons the increase were 2.1%-19.0%,3.4%-17.4%.(3)The test duration is about 45 days or so,the effect of water and nitrogen coupling on the number of flowering,and the number under the influence reached a significant level(p<0.05),the test showed that N2W1 treatment can improve the peanut flower number,compared with the lowest increase in 21.6%,and in the middle irrigation under the W2 level,the number of pods and seeds of peanut weight has a significant role.The correlation between yield and plant,root morphology and gray correlation analysis showed that the highest correlation and sensitivity indexes were root mean diameter,total root volume,lateral branch length and stem height.Adequate water and nutrients can promote the growth of underground and aboveground of peanut,and then increase pod yield.(4)The effects of water and nitrogen on chlorophyll content in peanut leaves were significant or highly significant at different stages.High chlorophyll content can significantly promote the photosynthetic rate,the effect of water and nitrogen control on peroxidase(POD)and catalase(CAT)activity were significant(p<0.01),and the single effect of water on CAT were significant,showing that the increase of irrigation amount will significantly promote the activity of CAT and the two together can delay peanut senescence and promote pod yield.In summary,in this study,N1W2 was selected as the optimal water and nitrogen control treatment.When the irrigation amount was 2810 m3hm-2(W2)and the nitrogen fertilizer was 15 kg N hm-2(Ni),it is conducive to promoting the growth of peanut and providing high yield and quality assurance.