Guizhou Orange Groves, Soil And Tree Nutrient Status And Evaluation

The problem which exist in the citrus production in Guizhou Province was studied.It bases on the actual production,use the methods which combine with production investigation,field sampling and laboratory analysis,and then study on the problems which relate to the development of citrus industry,for example,the nutrient status of citrus orchards on the citrus-producing areas of Guizhou Province,the problem of nutrient management in the fields,the diagnostic techniques of citrus nutrition,and the citrus balanced fertilization technology of high yield and high quality,it obtains the following main result.1.Reveal the citrus fertilizer status quo in citrus-producing areas of Guizhou Province,and define the main problems in the Citrus nutrient management.These areas are nutrient imbalances,the application rate of N,P and K are less than the average,the proportion of N,P and K are uncoordinated,the ratio of N and K are generally low,the amount and proportion of organic fertilizer are low,the application of nutrient distribution is inappropriate in different period.2.Explicitly the nutrient status of large,medium and trace element in the citrus tree and soil.69.23%of the citrus orchards in which the soil organic matter content low,the proportion are:N-80.5%,P-36.8%,K-72%,Ca-68%,Mg - 51.6%,Fe -5.6%,Mn-22.4%, Cu - 18.4%,Zn - 15.2%,Mo-76.92%,B-100%.The content of an effective part of Ca,Mg, Fe,Mn,Cu are excessive in part citrus-producing areas.In the main producing areas of Citrus,the nutrient lack respectively of leaf:N-42.8%,P-14.3%,K-14.3%,Ca-42.8%, Mo-100,B-28.6%;the nutrient lack respectively of navel orange leaf:N - 12.7%, Ca-81.8%,Fe- 1.8%,Zn-27.3%,and some leaf nutrient content excessive.3.Has been clear about the leaf blade nutrient content in navel orange and bumpsthe citrus,the average of the leaf nutrient content order:Ca-2.94%,N-2.41%,K-2.14%,Mg-0.47%, P-0.25%,Fe-142.7mg/kg,B-51.26mg/kg,Mn-54.18mg/kg,Zn-25.76mg/kg, Cu-6.05mg/kg,Mo-0.07mg/kg,the content variation condition of the two kind of main types citrus,the content of N,P,K,Mg are high in navel orange,the content of Ga and the Zn in citrus reticulata leaf blade is highest4.Study on the relationship between soil nutrients and leaves nutrient,the results showed that it were positively correlated between the soil pH and N,P,K and Mn, negatively correlated between the soil pH with Fe,Mg,Ga.that it were negatively correlated between the soil N and Cu,P and Fe Zn Cu and K and Fe Cu,positively correlated between the soil with other nutrients content.the citrus leaf blade nutrient content positively correlated between the leaf with N-K P-K P-Zn K-Zn,negatively correlated between the leaf with P-Ca P-Mg K-Ca K-Mg Ca-Fe Mg-Fe。5.In accordance with the outcome of the citrus growth and nutrient demand of the integrated fertilization,make balanced fertilization techniques which appropriate to the high-quality,high-yield and high efficient in Guizhou Province,the main techniques are that the soil and plant nutrition diagnosis,sub-regional because soil,fertilizer because of citrus types,organic and inorganic fertilizer combination of large and medium-sized trace elements of the entire match nutritional formula,adjusting the fertilizer application period for the period and the investment of nutrients,soil fertilization and foliar fertilizer and so on..