探讨了通过目标产量需磷量确定磷肥用量并在棉花生长早期集中施用的磷肥管理方法以维持适宜的土壤供磷强度、实现作物高产和磷肥高效利用目标的可行性,为磷肥减施增效提供依据.在新疆石河子选择中等供磷强度的农田(有效磷23.6 mg·kg-1),以覆膜水肥一体化棉花(Gossypium hirsutum)种植体系为对象,根据该区域2.7 t·hm-2皮棉产量的需磷量确定试验的磷肥用量(52.4kg·hm-2,以P计),开展了两年田间试验.试验选用三种不同性质的水溶性磷肥,设置不施磷肥(CK)、滴施磷酸一铵(MAP)、滴施磷酸脲(UP)和滴施聚磷酸铵(APP)4个处理.通过测定不同处理棉花的产量与磷吸收量,计算磷肥偏生产力(PFP)、磷肥农学效率(AEP)、磷肥当季利用率(PUE)与当季磷肥回收率(即作物吸磷量与磷肥施用量的比值);通过棉花不同生育期分层取样,分析了不同磷肥品种处理引起的土壤有效磷供应强度和无机磷形态组成的变化,以期阐明不同磷肥的空间有效性与棉花生长需求的匹配程度.研究结果表明:(1)施磷处理两年的皮棉产量平均为2.73 t·hm-2,达到了高产水平,MAP、UP和APP处理分别较CK增产21％、25％和11％;(2)施磷处理的磷盈余为2.2～4.8 kg,hm-2,磷肥当季利用率平均为24％,当季磷肥回收率为91％～96％;(3)磷肥在棉花蕾期和花铃期集中滴施,其垂直移动距离可达到20 cm 土层,能保证棉花生育期内的土壤供磷强度.与CK相比,施磷处理根区0～5cm、5～10cm、10～20 cm 土层的有效磷分别提高了 94％～302％、104％～144％和42％～67％.综上所述,将土壤有效磷供应强度维持在农学阈值附近、根据目标产量需磷量确定磷肥施用量,石灰性土壤上选择强酸性、缓释磷肥于作物生育前期集中施用能够在磷素输入-输出平衡的条件下实现作物高产和磷肥高效.根据平衡法计算的当季磷肥回收率能较好地反映磷肥的实际利用情况.
Input-Output Balance-Based P Fertilization Approach for Achieving Target Crop Yield and High P Use Efficiency:A Case Study of Cotton(Gossypium hirsutum L.)with Mulched Fertigation
[Objective]Maintaining moderate soil phosphorus(P)supply intensity and determining the P application rate based on the P requirement of the crop target yield,and combining with acid,slow-release water-soluble P fertilizers and applied in the early stages of crop growth is a novel P management approach in cotton.Here we test the feasibility and effectiveness of this method and provide a basis for reducing the P fertilizer application amount and increasing its use efficiency.[Method]A two-year field experiment was employed using cotton(Gossypium hirsutum)in the moderate Olsen-P soil(23.6 mg·kg-1)in Shihezi,Xinjiang.Based on the P requirement of the target lint yield of 2.7 t·hm-2,52.4 kg·hm-2 was selected as the P application rate.Four treatments were set-up with three types P fertilizers:(1)no P fertilizer(CK);(2)monoammonium phosphate(MAP);(3)urea phosphate(UP);and(4)ammonium polyphosphate(APP).It was analyzed that the lint yield,P uptake and above-ground biomass of cotton in different treatments.The partial productivity of P fertilizer(PFP),agronomic efficiency(AEp),P utilization efficiency(PUE)and P recovery index(the ratio of shoot P uptake to the amount of P fertilizer application,PRI)were calculated.Through stratified sampling,soil Olsen-P and P fractions in different soil layers were tested.Those allowed us to clarify the relationships between the P spatial availability and cotton growth requirements with different P fertilizers.[Result]The significant results were:(1)The average lint yield of P applied treatments in two years was 2.73 t·hm-2,which was classified as the high yield level in northern Xinjiang.Compared with the CK treatment,the lint yield of MAP,UP,and APP treatments were increased by 21％,25％,and 11％,respectively.(2)The P surplus was 2.2-4.8 kg·hm-2 and the P use efficiency was 24％across P applied treatments.The P recovery index of MAP,UP,and APP treatments was 91.7％,95.6％,and 94.8％,respectively.(3)P fertilizer applied by drip irrigation in the cotton bud and boll stages can move to the 10-20 cm soil layer,which may maintain the soil P supply intensity during the cotton-growing period.Compared with the CK treatment,the mean Olsen-P in P applied treatments were increased by 94％-302％,104％-144％,and 42％-67％in the 0-5 cm,5-10 cm,and 10-20 cm soil layers,respectively.[Conclusion]In summary,our results indicate that maintaining soil available P near the agronomic thresholds and determining the P application rate according to the P requirement of the target yield,and combining with acid,slow-release P fertilizer and applied in the cotton bud and boll stages can improve lint yield and P use efficacy under balanced P input-output conditions.Furthermore,the P recovery index based on the balanced P input-output can better reflect the real P use efficiency.
YieldAmmonium polyphosphateUrea phosphatePhosphorus use efficiencyCotton
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NSTL
万方数据
维普
