| The paper based on field experiments of the fertilizer and water-nitrogen coupling effects combined with technology of the plant quick test methods by the nitrate test strip. Dynamic monitoring on nitric nitrogen in soil and nitrogen nutrition diagnosis was implemented and soil profile analytical method was adopted. Fertilization model, water-nitrogen coupling hop model and the index of nitrogen nutrition diagnosis were established. The fertilization parameter and fertilizer absorption rule were studied ,the reasonable fertilizer and irrigation amount were confirmed, the soil nitrate nitrogen residue effects of fertilization and irrigation in soil were discussed. The results were as follows:1. Fertilizer effect model:Y= 1827+0.63N+4.44P+0.95K-0.014NP+0.021NK-0.011PK-0.000047N2-0.0018P2-0.015K2 (N,P,K represent urea and triple super-phosphate, potassium sulfate, respectively.) Prediction of the optimum rate of fertilizer application were urea 188kg/hm~2, triple super-phosphate 179kg/hm~2,potassium chloride 96 kg/hm~2,optimum yield 2355 kg/hm~2,respectively.2. Water-nitrogen coupling effect model:Y=1558.3+0.2X1-0.00002X12+1.0X2-0.002X22+0.0002X1X2 (X1,X2 represent irrigation amount and urea amount). Prediction results of the optimum application were optimum urea 181kg/hm~2, optimum irrigation amount 5319m3/hm~2, optimum yield 2483kg/hm~2 respectively.3. Results of nutrition coefficient were N 7.5～8.6 kg;P2O5 2.9～3.7kg;K2O 10.3～11.3 kg, respectively.The results of the N︰P 2O5︰K2O was 1︰0.4︰1.3. The Utilization rate of nitrogen fertilizer is 37.5%. Correction coefficient equation of alkali-hydrolyzable nitrogen is Y=0.0018X2-0.22X+7.91,(Y is correction coefficient X is alkali-hydrolyzable nitrogen )4.Studying fertilizer effect, each of the critical value of soil nitrate nitrogen was 12～32 and 10～19, 14～35mg/kg; the recommended urea rate was 138～268 and 165～274,157～265kg/hm~2 under condition of 0～30cm soil cone formation and 0～30cm soil cone autumn, 30～60cm soil cone autumn. The critical value of plant nitrate on hop flower and cone formation were 13.2～13.6×10~3 and 10.8～11.1×10~3mg/kg. The first and second top-dressing urea amounts were 55～108 and 70～115kg/hm~2. The total urea amount was 200～298 kg/hm~2 during whole growth period. Both of the soil and plant nitrogen nutrient diagnosis could recommend for nitrogen application of hop. Studying water-nitrogen coupling effect, each of the critical value of plant nitrate was 9816～9926 and 9783～9955, 8584～8932mg/kg under period of bud and flower, cone formation. The first top-dressing urea recommended of quantities was 20～63 kg/ hm~2.The second top-dressing urea amount was 22～55 kg/ hm~2. The total urea amount was 117～193 kg/hm~2 during whole growth period.5. On fertilizer effect, study of the spatial distribution of soil nitrate nitrogen shows that soil nitrate nitrogen on flower and cone formation has different degree of leaching phenomenon; soil nitrate nitrogen had no significantly accumulation when urea application was 150～300kg/ hm~2. On water-nitrogen coupling effect, study of different period of soil nitrate nitrogen accumulation and vertical distribution show that nitrate nitrogen content and accumulation on soil section increased with increasing of nitrogen fertilizer application; the degree of leaching phenomenon increased with increasing of irrigation requirement. Studied on the section of distribution of rudimental soil nitrate nitrogen, it showed that soil nitrate nitrogen content was lower when close to the main root. The distribution of root system had very important effect on the distribution of soil nitrate nitrogen.
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