Application Effect of Integrated Water and Fertilizer Technology for Tomato

Integrated water and fertilizer technology has the advantages of saving water,fertilizer and labour,which is widely applied in tomato plantation. Integrated water and fertilizer technology in topdressing and whole process of big and small tomatoes were studied,and their application effects were contrasted and analyzed,and application advantages and scopes of the two models were concluded.

Fertilization Status and Soil Nutrient Condition in Some Asparagus Production Regions of Zhejiang Province

Asparagus is delicious,with rich nutrition,and it is one of main economic crops in Zhejiang Province.In this paper,by investigating fertilization situations of farmers in several asparagus production regions(Fuyang,Pinghu,Changxing and Cixi) and soil nutrient condition of asparagus garden with different plantation years,fertilization status and nutrient condition of asparagus garden were described,and fertilization suggestion was proposed,which aimed to guide scientific fertilization of asparagus and promote healthy development of industry.

Detection and Discrimination of Tea Plant Stresses Based on Hyperspectral Imaging Technique at a Canopy Level

Tea plant stresses threaten the quality of tea seriously.The technology corresponding to the fast detection and differentiation of stresses is of great significance for plant protection in tea plantation.In recent years,hyperspectral imaging technology has shown great potential in detecting and differentiating plant diseases,pests and some other stresses at the leaf level.However,the lack of studies at canopy level hampers the detection of tea plant stresses at a larger scale.In this study,based on the canopy-level hyperspectral imaging data,the methods for identifying and differentiating the three commonly occurred tea stresses(i.e.,the tea leafhopper,anthrax and sun burn)were studied.To account for the complexity of the canopy scenario,a stepwise detecting strategy was proposed that includes the process of background removal,identification of damaged areas and discrimination of stresses.Firstly,combining the successive projection algorithm(SPA)spectral analysis and K-means cluster analysis,the background and overexposed non-plant regions were removed from the image.Then,a rigorous sensitivity analysis and optimization were performed on various forms of spectral features,which yielded optimal features for detecting damaged areas(i.e.,YSV,Area,GI,CARI and NBNDVI)and optimal features for stresses discrimination(i.e.,MCARI,CI,LCI,RARS,TCI and VOG).Based on this information,the models for identifying damaged areas and those models for discriminating different stresses were established using K-nearest neighbor(KNN),Random Forest(RF)and Fisher discriminant analysis.The identification model achieved an accuracy over 95%,and the discrimination model achieved an accuracy over 93%for all stresses.The results suggested the feasibility of stress detection and differentiation using canopy-level hyperspectral imaging techniques,and indicated the potential for its extension over large areas.

Effect of Balanced Application of Potash Fertilizer on the Yield of Rice Yongyou 15 and Soil Nutrient Content

By the field experiment,we set up the treatments of non-application of potash fertilizer,conventional fertilization,balanced fertilization and halved application of potash fertilizer,and studied the effect of different treatments on rice yield and soil nutrient content. The results showed that compared with non-application of potash fertilizer,conventional fertilization and balanced fertilization significantly increased the spike length,thousand kernel weight,yield and total potassium content of the stalk,as well as soil organic matter,total nitrogen and available phosphorus content; compared with conventional fertilization,the balanced fertilization did not significantly increase the rice growth and yield,but effectively increased rice grain total nitrogen,stalk total nitrogen and total phosphorus content,as well as soil available phosphorus and available potassium content. It could be found that potash fertilizer played a certain role in increasing rice yield and soil nutrient content,and the balanced fertilization had the most significant effect.