水、氮和保水剂对小粒咖啡水氮利用的影响

为探求小粒咖啡幼树的最佳水氮管理及高效利用模式,通过2种灌水水平（中水（WM,65%～80%FC）和低水（WL,50%～65%FC））、3种施氮水平（高氮（NH,0.40g/kg）,低氮（NL,0.20g/kg）和无氮（Nz,0））和2种保水剂水平（有保（SH,1kg/m^3）和无保（SZ,0））的完全处理组合,研究灌水、氮素营养及保水剂对小粒咖啡幼树根区土壤水氮累积、干物质生产和水氮吸收利用的影响.研究表明：和WL相比,WM提高总干物质量、水分利用率、氮素吸收总量和氮素干物质生产效率分别为86.0%,36.4%,73.1%和5.3%.和NZ相比,NL和NH提高水分利用率和氮素吸收总量的效果基本相同.和SZ相比,SH提高土壤硝态氮质量比、总干物质量、水分利用率和氮素吸收总量分别为21.9%～43.0%,78.3%,68.9%和91.2%,而降低氮素干物质生产效率10.0%.在中等供水（65%～80%FC）和低氮（NL,0.20g/kg）条件下,配施保水剂能有效调控土壤水氮供给状况,促进干物质生产和提高水氮利用效率.因此,在本试验条件下,有利于小粒咖啡水氮高效利用的最优试验组合为WM NL SH.

Effects of soil moisture,nitrogen and superabsorbent polymers on water and nitrogen use of arabica coffee

To explore the optimal mode of water and nitrogen management and effective utilization of young arabica coffee tree,using two water levels,i.e.middle water WM,65%～ 80%of soil field capacity（FC） and low water（WL,50%～65%FC）,three nitrogen levels,i.e.high nitrogen（NH,0.4 g/kg air-dried soil）,low nitrogen（NL,0.20 g/kg air-dried soil） and no nitrogen（NZ,O）,two SAP levels,i.e.added SAP（SH,1 kg/m^3） and no SAP（SZ,O）,the effects of soil moisture,nitrogen and superabsorbent polymers（SAP） on accumulation of water and nitrogen,dry mass production and use of water as well as nitrogen in root-zone of young arabica coffee tree were studied.The results show that,compared to WL,Wu can increase total dry mass,water use efficiency（WUE）,total nitrogen uptake（TNU） and nitrogen dry matter production efficiency（NDMPE） by 86.0%,36.4%,73.1%and 5.3%,respectively.Compared to NZ,NL and NH has the same effect on WUE and TNU increment.Compared to SZ,SH can increase soil NO3^-- N content,total dry mass,WUE and TNU by21.9%～43.0%,78.3%,68.9%and 91.2%,respectively,while NDMPE is redued by 10.0%.Under the condition of middle water（65%～80%.FC） and low nitrogen（0.2 g/kg dry soil）,SAP can effectively regulate soil moisture and nitrogen environment,and can promote dry mass production and increase water and nitrogen use efficiency.Tlierefore,WMNLSH is the optimum combination of water and nitrogen efficient use in the experiment.