Effects Of Different Forms And Proportions Of Nitrogen On The Available Nutrients Content And Enzymes Activities In Winter Wheat Field

The research, combining field trials with laboratory analysis, was conducted on the farm ofKaiyuan campus of Henan University of Science and Technology, Luoyang City, Henan Provincefrom2010to2012. This essay studied the effects of five different forms and proportions ofnitrogen （NH+-4-N:NO3-N were0:100,25:75,50:50,75:25and100:0, referred to afterwards as N1,N₂, N₃, N₄and N5respectively） on the content of hydro-N*, available P, available K and activitiesof catalase, protease, urease, invertase and amylase in rhizosphere soil and non-rhizosphere soil ofstrong gluten wheat Zhengmai366, medium gluten wheat Zhoumai22and weak gluten wheatZhengmai004. The results showed as following:1. Effects of different forms and proportions of nitrogen on available nutrients content in winterwheat fieldThe content of hydro-N*showed a trend of decrease, increase, and again decrease; thecontents of available P and available K both decreased gradually; and the available nutrientscontent in rhizosphere soil of the three different wheats were all higher than in non-rhizosphere soilwith wheat growth.And the comparison between the five different treatments showed that treatment N₂（with aNH₄⁺-N:NO₃^--N ratio of25to75） effectively improved the content of hydro-N*, available K in thein the rhizosphere soil and non-rhizosphere soil of Zhengmai366and Zhengmai004, as well as thecontent of available P in their rhizosphere soil, and at the same time, significantly improved thecontent of available P, available K in the soil of Zhoumai22; whereas treatment N₃（with a NH+4-Nand NO₃^--N ratio of50to50） was more conducive to the elevation of the content of available P innon-rhizosphere soil of Zhengmai366and Zhengmai004, as well as the content of hydro-N*inrhizosphere soil of Zhoumai22.2. Effects of different forms and proportions of nitrogen on enzymes activities in winter wheat fieldWith wheat growth, under the five proportions of nitrogen forms treatments, the catalaseactivity in rhizosphere soil and non-rhizosphere soil of the three varieties of wheat all showed a general trend of growth at first, then a rapid decline at the flowering stage, finally growth again atthe mid-grouting stage; the protease activity showed a general trend of growth before decline; aswheats grow, the invertase activity in rhizosphere soil and non-rhizosphere soil, including amylaseactivity in rhizosphere soil all showed a trend of “M”, and amylase activity in non-rhizosphere soilshowed a trend of decline, growth, and decline again at maturity stage.Comparison between the above-mentioned treatments proved that treatment N₂（with aNH+4-N and NO-3-N ratio of25to75） could effectively improve the catalase activity and invertaseactivity in the soil of the three different wheats, and could considerately improve the proteaseactivity in rhizosphere soil and non-rhizosphere soil of Zhengmai366and Zhengmai004, amylaseactivity in rhizosphere soil and non-rhizosphere soil of Zhengmai366, as well as the amylaseactivity in the rhizosphere soil of Zhoumai22; while treatment N₃（with a NH₄⁺-N and NO₃^--Nratio of50to50） was more conducive to the elevation of urease activity in rhizosphere soil andnon-rhizosphere soil of Zhengm-ai366and protease activity and amylase activity innon-rhizosphere soil of Zhoumai22, as well as amylase activity in rhizosphere soil of Zhengmai004;and treatment N₄（with a NH4_<sup>+-N and NO₃^--N ratio of75to25） could effectively improve theurease activity in the soil of Zhoumai22and Zhengmai004, as well as the protease activity inrhizosphere soil of Zhoumai22.3. Effects of different forms and proportions of nitrogen on the yield of the three different wheatsDifferent forms of N ratio lead to different yields for the three different wheats: treatment N₄（with a NH+4-N and NO-3-N ratio of75to25） could effectively improve the yield of strong glutenwheat Zhengmai366, and treatment N₂（with a NH₄⁺-N and NO₃^--N ratio of25to75） was moreconducive to the elevation of the yield of weak gluten wheat Zhengmai004; medium gluten wheatZhoumai22yield was the highest under treatment N₃（with a NH₄⁺-N and NO₃^--N ratio of50to50）...