The Evolutionary Regularity Of Soil Potassium Pools Of Farmland Phaeozem

This article take the black soil as the object of study, The investigation sampling, the indoor analysis and a long field experiment were carried out study the effects of different reclamation years and the agricultural measures on the black soil potassium pools, In order to investigate the evolutionary regularity of the black soil potassium pools, maintain the black soil potassium nutrient the best dynamical equilibrium, the good showing farmland nutrient balance condition, displays the soil fully for the potassium potential, provides the scientific basis for the potassium fertilizer reasonable employment.The result showed that reclamation has certain influence to the black soil potassium pools. Along with reclamation years increase, the total potassium content tends the reduction, the change scope is small. Reclamation 200 years (16.29g/kg) to be opposite in the open land (22.91g/kg) the total potassium quantity reduced 18%; The soil readily available potassium content dropped, reclamation 200 years black soil readily available potassium (120mg/kg) to be opposite in the non reclamation black soil (250mg/kg) reduces 56%, the decline rate has been quite big; The soil slowly available potassium content increased, reclamation 200 years black earth slowly available potassium (1350mg/kg) to be opposite in the non reclamation black soil(790mg/kg) enhanced 72%, increased the scope to be big; But the mineral potassium change is small, reclamation 200 years black earth (14.82g/kg) to be opposite in non reclamation black soil (31.84g/kg) reduced 22%. The reclamation has the tremendous influence to the soil readily available potassium and slowly available potassium pools of the easily absorption use by the plant soil, but has the small influence to the mineral potassium pools.The effect of the different fertilization measures on the soil different forms potassium content were different. And the effect of fertilization on total potassium content were not obvious, the total potassium content range of variation (21.94-20.32g/kg), the readily available potassium content change scope were 226.0mg/kg-136.5mg/kg. and compared to CK, in SRMNPK treatment the readily available potassium pools content increased 63.7%, slowly available potassium range of variation were (992.3- 867.0mg/kg). Compared to CK , in SRMNPK treatment the slowly available potassium contents increased 13.86%, but he slowly available potassium contents reduced in long time non the organic fertilizer treatment, only fertilizer treatment reduced 14.86%. The effect of fertilization treatment were small to the mineral potassium, mineral potassium range of variation (19.29-20.72g/kg). In SRMNPK, RMNPK and SMNPK treatment the total potassium pools and the readily available potassium pools contents were the highest, these three kinds fertilization measures were the most superior treatment, the straw stalk also field organic fertilizer and the chemical fertilizer match execute play the poising action to the soil potassium pools.After the corn had harvested, the readily available potassium content reduced in compare to sowing seeds. However, due to large amount of fertilization, plant absorption of potassium overdose, a potassium "leakage" phenomenon,In NPK5 treatment the soil readily available potassium content was increasing. With the rates of potassium fertilizer decreasing ,the slowly available potassium markedly improved. Generally speaking, the soil slowly available potassium contents change were much smaller than the readily available potassium. The potassium content of corn grain were low In corn mature period, and the effect of fertilization treatment on it were less. The potassium content of corm stem were higher, and with the increasing of potassium fertilizer rates ,the potassium content of corm stem were increasing, and the potassium content of grain were about 1.6 to 2.2 times.The total absorption of potassium by shoot and potassium balance results in soil , the soil potassium removal by corn aevial parts were much more in non fertilizer treatment and only NP fertilizer treatment. For only NP treatment increased output, the consumption of potassium increased. With Improve the application of potash fertilizer, That the potassium in soil taken off by corn were significantly increased ,and potassium fertilizer utilization rate decreased ,when the application of potash fertilizer in the 117 kg kg/hm~2, the loss of potassium in the soil, could not remain in the soil potassium Balance.Under the different cropping system the black soil potassium pool change were different. The soil total potassium, the slowly available potassium, the readily available potassium and the mineral potassium content displays for the continuous cropping is higher than crop rotation treatment, looking from the soil layer (0-30cm) the mean value, the crop rotation and the continuous cropping treatment to the soil total potassium and the mineral potassium content influence were not big, the continuous cropping (24.93g/kg) (24.28g/kg) compared the total potassium content with the crop rotation to differ 0.65 g/kg, the continuous cropping (24.38g/kg) (23.57g/kg) has compared the mineral potassium with the crop rotation to differ 0.81 g/kg; Is relatively big to the soil slowly available potassium and the readily available potassium influence, the continuous cropping (143.2mg/kg) (109.4mg/kg) compared readily available potassium 33.8 mg/kg with the crop rotation, the continuous cropping (592.16mg/kg) (565.57mg/kg) compares the slow effect potassium with the crop rotation to differ 26.59 mg/kg. The effect of continuous cropping on the soil potassium pools were bigger.In the 0-30cm soil layer, The effect of the different cropping system on the different form potassium in soil distribution situation were different. The maximum content of total potassium and the mineral potassium in continuous cropping and crop rotation treatment all were in the 5-10cm soil layer; The maximum content of slowly available potassium in continuous cropping treatment were in 10-20cm, and the crop rotation were in 0-5 cm; The maximum content of readily available potassium in continuous cropping treatment were in 0-5cm, and the crop rotation treatment were in 20-30cm. But the relationship of different treatments were not significant.Different cultivation measures on the black soil potassium have a certain impact. In the different treatment the content of soil total potassium, readily available potassium and mineral potassium all were over autumn (24.28 g/kg, 138.5mg/kg, 23.57g/kg)