Effects Of Different Water And Nitrogen Coupling And Mulching On Growth, Yield And Nutrient Uptake Of Medlar

There is a significant interaction between water and fertilizer, high yield of crop needscertain ratio of water and fertilizer, not when high water and high fertilizer that the yield andquality of crop is optimal；Mulching has the effect of retaining water、retaining fertilizer、warming、improving soil properties, it also has the function of improving soil fertility、reducing pest and reducing humidity when in continuous rain. This study has the test in theefficient water-saving agricultural technology park of Ningxia with using wolfberry species"Ningqi7" of three years medlar tree as test material, with whether mulching、three levels ofirrigation amount and three levels of nitrogen fertilizer amount, a total of three factors andeighteen leveals as different treatment, using furrow irrigation. The research studied theeffects of different water and nitrogen coupling and mulching on soil temperature、soilmoisture、soil nitrate content、crop physiological characteristics and crop yield, explored theinteraction of water and nitrogen coupling and differences when in no mulching or mulching，which can provide a reference value for establishing water and nitrogen coupling model ofmedlar and determining whether need to mulch.Through the field experiments in2013andtheoretical analysis, finally get the following basic conclusions:(1) In the whole growth period of the autumn medlar,the average temperature trends of0to25cm soil under the surface under each treatment are basically the same, the average soiltemperature of each treatment showed decreased overall trend with the growth period of theautumn medlar, the soil temperature is start to low from August23, so choosing mulchingbefore August23to improve soil temperature. Mulching compare to no mulching, whenunder low water that the influence of different nitrogen treatments on soil temperature isopposite, while under middle water and high water that the influence decreases.Thetemperature of0to15cm soil under each treatment has significant difference (P <0.05), thetemperature of15to25cm soil under each treatment has no significant difference (P <0.05).(2) The crop water consumption was greater than the rainfall in the whole growth periodof the autumn in the region in2013, the treatment of crop water consumption in descendingorder: high water and high nitrogen under mulching＞high water and middle nitrogen under mulching＞middle water and middle nitrogen under mulching＞high water and low nitrogenunder mulching＞high water and middle nitrogen under no mulching＞low water and lownitrogen under mulching＞low water and middle nitrogen under mulching＞middle water andlow nitrogen under no mulching＞middle water and high nitrogen under no mulching＞middle water and middle nitrogen under mulching＞high water and high nitrogen under nomulching＞high water and low nitrogen under no mulching＞high water and low nitrogenunder mulching＞middle water and middle nitrogen under no mulching＞middle water andlow nitrogen under mulching＞low water and low nitrogen under no mulching＞low waterand middle nitrogen under no mulching＞low water and high nitrogen under no mulching；mulching compare to no mulching, the magnitude of change of the average soil moisture withsoil depth is smaller;the soil moisture of the middle water and low nitrogen under nomulching, the low water and low nitrogen and high water and high nitrogen under mulchingwas higher, and its change with the growth period of the autumn medlar was smaller,whichcan provide a better water supply for medlar than other treatment,which more conducive tothe growth of crops.(3) When the amount of nitrogen fertilizer was not more than that of middle water andmiddle nitrogen treatment, as the amount of irrigation was greater,the average relative residualnitrate content of was lower, the efficiency of nitrogen was higher;while the amount ofnitrogen fertilizer was more than that of middle water and middle nitrogen treatment,itshowed the opposite trend between mulching and no mulching.The average nitrate content ofthe0to200cm soil showed the trend of all increased first, then decreased and finallygradually stabilized to a certain value with the growth period. mulching compare to nomulching, The average nitrate content was on the20cm lower, the average nitrate content ofthe140to200cm soil showed the gradually decreasing trend with the soil depth increases, Inthe soil at a depth of200cm, the nitrate content of all treatment was decreased to the lowerlevel.(4)The irrigation and nitrogen application on the length and diameter of crude ofwolfberry autumn pumping branch had significant effect(P<0.05), mulching had nosignificant effect(P<0.05), the interaction between irrigation and nitrogen fertilizer wassignificant (P<0.05), other interaction had no significant effect(P<0.05). The irrigation、nitrogen application and mulching on medlar yield had highly significant effect(P<0.01)，theinteraction between each two factors had highly significant effect(P<0.01)，three had nosignificant interactions between the three factors(P<0.05).The yield of medlar under middlewater and middle nitrogen under no mulching which used by local was not the biggest， the yield of the high water and high nitrogen under no mulching, the high water and highnitrogen and middle water and low nitrogen under mulching was higher.