Potassium Nutrition Diagnosis Of Sugar Beet Based On Plant Potassium Concentration Rapid Measurement Technology

In order to explore the feasibility of using the rapid measurement technology of potassium ion concentration in plant petiole to diagnose the potassium nutrition of sugar beet,and the application of this technology to establish the topdressing model,this thesis used the handheld potassium ion meter to determine the potassium ion concentration in the petiole.At the same time,the feasibility of using the handheld potassium ion meter to diagnose the potassium nutrition of sugar beet was verified by using the flame photometry and the potassium content of leaf,petiole and root,combined with the soil diagnosis technology,and the sugar beet potassium nutrition diagnosis method and potassium fertilizer recommendation system based on the petiole potassium ion test were established.The following results are obtained:1.Reasonable application of potassium fertilizer can better promote the absorption and utilization of potassium nutrients in sugar beet,increase the dry weight of root,petiole and leaf,and the sugar content of sugar beet increases first and then decreases with the increase of potassium application rate.After the excessive supply of potassium in sugar beet,the root yield no longer increased with the increase of potassium supply,while the aboveground part of sugar beet still absorbed potassium.2.The correlation between potassium concentration and potassium gradient in the fifth petiole of sugar beet was the highest,which could be used as an index for rapid diagnosis of potassium nutrition in sugar beet by hand-held potassium ion meter.3.The critical value of potassium concentration in the fifth leafstalk of’KWS1197’and’HI1059’sugar beet varieties in Linxi area was determined at seedling stage（SS）,leaf rapid growth period（LGFS）,root and sugar growth period（RSIS）and sugar accumulation period（SCAS）.The critical potassium concentration of KWS1197 is 4684ppm,5467 ppm,3957 ppm,3611 ppm;the critical potassium concentration of HI1059 is4762 ppm,5376 ppm,3385 ppm,3353 ppm.4.In the Linxi area,from the seedling stage to the sugar accumulation period of four growth periods,’KWS1197’sugar beet varieties of potassium nutrition field rapid diagnosis and potassium fertilizer recommendation model is:The actual potassium fertilizer application rate of leaves from rapid growth period:K_SS=36.51×[1+(307-K_real)/307];The actual application amount of potassium fertilizer during root differentiation and formation period:K_LGFS=25.91×[1+(184-K_real)/184];The actual application amount of potassium fertilizer in root and sugar growth period:K_RSIS=44.64×[1+(378-K_real)/378];The actual application amount of potassium fertilizer in sugar accumulation period:K_SCAS=48.37×[1+(377-K_real)/377].The potassium nutrition field rapid diagnosis and potassium fertilizer recommendation model of’HI1059’beet variety were as follows:The actual potassium fertilizer application rate of leaves from rapid growth period:K_SS=45.95×[1+(326-K_real)/307];The actual application amount of potassium fertilizer during root differentiation and formation period:K_LGFS=34.28×[1+(244-K_real)/184];The actual application amount of potassium fertilizer in root and sugar growth period:K_RSIS=44.16×[1+(314-K_real)/378];The actual application amount of potassium fertilizer in sugar accumulation period:K_SCAS=45.73×[1+(325-K_real)/377].