Study On Nutritional Diagnosis Technique Of Soil In Sweet-cherry Orchards In Yantai

To study the relationship between soil organic matter, alkaline hydrolysis nitrogen, available P , available K and the production and the status of effective nutrition in soil, nutritional diagnosis technique about soil was used in 1105 selected representative sweet-cherry orchards in Yantai of Shandong province from 2006 to 2007. The main results were as follows:The average content of organic matter in sweet-cherry orchards in Yantai was 1.14%, the content of alkaline hydrolysis N was 74.9 mg.kg^-1, available P was 40.9 mg.kg^-1, available K was 122.7mg.kg^-1 ; According to the soil available nutrition contents standard of orchards in Shandong province, the soil nutrition feature of sweet-cherry orchards in Yantai is that organic matter is low, alkaline hydrolysis N is high and polarizated, available P is low and available K is low, too. The analysis of more than 110 soil samples showed that the relationship between soil organic matter, alkaline hydrolysis N, available P and available K and the production can be expressed by a second order equation with one variable which were y=-192.04x²+1735.7x-517.01, y=-0.0955x²+31.546x-878.8,y=-0.0387x²+ 15.947x + 266.63 and y=-0.0828x²+27.233x-482.35, and R²were 0.4188 ,0.3635,0.326 and 0.3127. The result showed that if the level of alkaline hydrolysis N is under 100mg.kg^-1, available P under 70 mg.kg^-1, available K under 100 mg.kg^-1, the yield increased with the increasing of the available nutrition. The contents of lkaline hydrolysis N, available P, and available K of soil in the higher-yield orchards are higher than those in the lower-yield orchards. It can be concluded that the soil available nutrition is one of the most important factors in increasing the production. Compared with lower-yield orchards, the alkaline hydrolysis N increased 15.1%, available P increased 70.0%, available K increased 24.9% in higher-yield orchards.The P and K increased much, and these are the main limiting factor of the increase of the production. You must increase the effective nutrition of the soil properly, especially the content of available K, if you want to increase the production of lower-yield orchards. The proposed ratio of N,P and K is 1:0.65:1.34.The nutrition status in different organs of sweet-cherry trees were various in different phenophases. The distribution of N in the leaves was the most, and that in the root was less, in the new organs were the least. With the delay of the phenophases, the content of P decreased gradually. The content of K increased first and then decreased.The content of Ca increased in the early stage, reached the highted level at core hardening stage, then it changed little. The content of Mg also increased first and reached the hightest level at core hardening stage,it changed little from core hardening stage to flower differentiation stage. The content of Zn increased in the early stage and reached the higetest level at core hardening stage, then it began to decrease, and it increased little after harvest. The content of Fe reached the hightest level at harvest stage, then increased little. According to the requirements for the nutrition of the new organs, we got the annual demand for fertilization in sweet-cherry trees, and make it as a standard demand for fertilization.That is 306 kg/hm²N, 153 kg/hm²P₂O₅, 306 kg/hm²K₂O.According to the effective nutrition in the soil, we should fertilizer at fitting situation: that is increase 25% of the fertilization if the testing result of soil is lower, increase 50% if the testing result of soil is the least, and we should increase 100% if the alkali hydrolysable N is less than 20 mg.kg^-1 , available P (P₂O₅) is less than 5 mg.kg^-1, available K (K₂O) is less than 25 mg.kg^-1. We should decrease 25% of the fertilization if the testing result is highter, decrease 50% if the testing result is the highest, and we should control the application if the alkali hydrolysable N is more than150 mg.kg^-1, available P (P₂O₅) is more than 100mg.kg^-1, available K (K₂O) is more than 400 mg.kg^-1.According to the test of fertilization in ten orchards, we found that the orchards which fertilizer prescribed will increase 455kg in every 667m² towards those fertilizer conventionally, carbohydrate will increase 0.58%, and people's income will increase more than 2,400 yuan. Prescribed fertilization according to the soil effective nutrition is notable.