| Potassium has become one of the nutrition limiting factors in the black soil of Jilin province. The effect of potassium fertilizer was related to the capacity of soil K fixation and supplying, type of crop and varieties, and the condition of other nutrition element in the soil and fertilizer. While the capacity of K fixation and supplying oh the soil was related to type of the soil, and the ecological factors of the soil such as water contents, temperature and the climate factors. Corn is the first crop of the black soil in the Jilin province, and so with the systems analysis of soil nutrition, and with the experiments of soil potassium exhausting and filed fertilizer application, the soil potassium fixation capacity and supplying capacity, its relation with the fertilization , and the potassium uptake of the corn plant were studied. The results as followed.1. The amounts of potassium fixation in the black soil was correlated to the amounts of Kfertilization, and it increased with the addition of K fertilization within 0~4000mg K 2O /kg soil, but then tend to be stable slowly when the amount of potassium fertilization was high enough.2. In all the high, moderate and low fertile black soil, the plant biomass decreased with thecutting down of potassium fertilization from the OPT, and the same results was got in the filed potassium fertilization experiment. And it is suggested that potassium has become one the limiting factors in crop production in black soil.3. The exhausting experiment showed that the exchangeable potassium decreasedquickly during the soil exhausting, and decreased by 48%~50.3% at the third planting, became stable at the eighth planting. The total amounts of potassium supplying in the black soil was 102-129 mg/kg , the difference between the contents of exchangeable potassium in soil before planting and the stable contents could be index of the available supplying potassium in the soil .4. During the exhausting, the potassium potassium uptake of corn plant decreasedgradually, and decreased to the stable amounts at sixth to eighth planting. The plant uptake of potassium showed the same curve with the exchangeable potassium in the soil during exhausting.5. The amounts of potassium supplying increased with the increase of soil fertile, and itwas 115.9, 93.8 and 64.5 kg /ha in the high, moderate and low fertile soil. Also the amounts of potassium supplying increased with the increase of plant uptake during the corn plant growth and development.6. The amounts of potassium supplying was related to the uptake capacity of corn variety.Among the six corn varieties in the plot, SIMI NO. 21 showed the strongest ability of potassium uptake which uptaked 74.6 Kg/ha K2O during the life, and YEDAN NO. 54 showed the lowest ability which uptaked 54.5 Kg/ha K2O during the life.7. The fastigium of corn plant potassium uptake presented during the eleventh leaf stageto tassel stage. The ratio of potassium uptake at the tassel stage to the total uptake during life was 93.1%, 100%, 100%, 99.3%, 96.7% and 63.2% for the DAN NO. 703, SIDAN NO. 48, YEDAN NO. 54, DANZHAO NO. 208, SIMI NO. 21 and SIDAN NO. 2 respectively. All the varieties except SIDAN NO.2 almost stop uptake after tassel stage.8. The corn plant absorbing and utilization of potassium fertilizer was related to the soilfertile. Under the same application of nitrogen and phosphate fertilizer and lOOkg/ha K20, the ratio of corn plant absorbing and utilization of potassium fertilizer were 27.4%, 34.4% and 51.3% in the high, moderate and low fertile soil respectively. And the potassium supplying capacity and fixation capacity could be one of the causes for the results.9. Amounts of potassium for lOOKg corn grain production varied among the varieties. TheSIDAN NO. 2 showed the highest of 2.56Kg , and then DAN NO. 703 2.33kg , the lowest amounts of 2.02-2.08 belonged to DANZHAO NO.208 and SIMI NO. 21.10. Potassium can affect the uptake of other nutrition elements, suitable pot... |
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