Abstract:In order to apply phosphorus fertilizer reasonably in irrigated grey desert soil, six treatments were set up through soil culture test to study the effects of phosphate fertilizers and application methods on soil Olsen-P and inorganic phosphorus forms.The six treatments include no phosphate fertilizer (CK), the basal application of triple super phosphate (TSP-B), the basal application of mono-ammonium phosphate (MAP-B), the basal application of ammonium polyphosphate (APP-B), the one time drip application of mono-ammonium phosphate (MAP-D) and the one time drip application of ammonium phosphate (APP-D).The results indicate that the content of Olsen-P in 0-20 cm soil layer was significantly reduced with the culture time under basal application of 3 kinds of phosphate fertilizers (TSP, MAP-B and APP-B), and the contents of Olsen-P in 5-10 cm soil layer treated with MAP and APP through one time drip application (MAP-D and APP-D) had trended increasingly with the culture time.The Ca10-P and O-P were the main inorganic phosphorus in irrigated grey desert soil under no application of phosphate fertilizer,which accounted for 47.94% and 23.76% of the total inorganic phosphorus amount, respectively.The basal application of 3 kinds of phosphate fertilizers could improve the contents of Olsen-P, the total inorganic phosphorus amount and the proportion of Ca2-P, Ca8-P, Al-P and Fe-P in 0-20 cm soil layer in irrigated grey desert soil,but the above contents and the proportion had no significant difference among TSP, MAP-B and APP-B.Compared with basal application of MAP and APP, one time drip application only significantly improved the contents of Olsen-P in 0-5 cm soil layer of grey desert soil, total inorganic phosphorus amount and the proportion of Ca2-P and Ca8-P, significantly reduced the proportion of Ca10-P, and boosted the phosphorus supply ability of 0-5 cm soil layer.To sum up, the basal application of 3 kinds of phosphate fertilizers can enhance the phosphorus supply ability of 0-20 cm soil layer, and the one time drip application of MAP and APP only significantly boosts the soil phosphorus supply ability of 0-5 cm soil layer.Therefore, in production practice, it is suggested selecting the cheap triple super phosphate basal application. |