| Testing analysis indicates that the average content of quick-acting K2O in the main soil in Hexi corridor is 122.31 mg/kg. Compare with 164.83 mg/kg at the time of the overall survey of soil in 1985,it has dropped relatively by 27.05%;Test of the potassium field fertilizer efficiency shows that the optimum amount of fertilization for potato,pimento,squash,tomato,cucumber, celery,beet K2O is 239.70,299.85,296.10,225.00,428.10,119.95 and 355.51 kg/hm2 respectively,with which the theoretic output is 63.45,68.38,75.52,113.53,94.67,90.17,112.48 t/hm2 respectively.The profit of potassium application for different crops is: cucumber>potato>squash>pimento>celery>tomato>beet. |