摘要:依托甘肃平凉定位试验（1979年-），分析长期不同施肥下土壤磷素和磷肥效率的演变特征，为黄土旱塬雨养农田合理施用磷肥提供参考。试验包括6个处理：不施肥（CK）、单施氮肥（N）、氮磷配合（NP）、秸秆还田加氮和隔年施磷（SNP）、单施农家肥（M）和农家肥加氮磷（MNP），种植制度为4年冬小麦-2年春玉米的一年1熟轮作制。结果表明，试验进行38年后，长期无磷投入（CK、N）处理耕层土壤全磷和Olsen-P含量及磷活化系数比试验开始时下降，而施磷处理（NP、SNP、M和MNP）土壤全磷分别增加22.8%、14.0%、38.6%和56.1%，Olsen-P相应提高99.1%、48.4%、206.4%和375.6%，磷活化系数分别是开始时的1.7倍、1.3倍、2.2倍和3.1倍。随试验年限延长，CK处理耕层土壤全磷基本不变；N和SNP耕层土壤全磷呈下降趋势，每年下降速率为1.9 mg·kg-1和2.6 mg·kg-1；NP、M和MNP处理呈增加趋势，每年增加速率分别为1.2 mg·kg-1、1.9 mg·kg-1和2.8 mg·kg-1。CK和N处理Olsen-P呈下降趋势，年下降速率分别为0.03 mg·kg-1和0.09 mg·kg-1；NP、SNP、M和MNP处理土壤Olsen-P呈增加趋势，年增量分别为0.29 mg·kg-1、0.24 mg·kg-1、0.46 mg·kg-1和0.89 mg·kg-1。作物产量与耕层土壤Olsen-P含量呈极显著正相关（小麦R2=0.116 9，n=132；玉米R2=0.332 4，n=54）。施磷处理（NP、SNP、M和MNP）玉米的磷肥回收率、利用率和农学效率大于小麦，而生理效率小麦大于玉米；各处理磷肥效率4个指标的大小顺序均为SNP > NP > MNP > M，玉米磷肥效率的4个指标都随试验年限延长而提高。M较MNP处理P投入减少了14.2%，小麦、玉米磷素效率降低14.3%~69.5%、0.8%~75.5%。总之，有机无机结合是黄土旱塬区培肥地力、提高作物产量和资源利用效率的施肥措施。
关键词:黑垆土/
长期施肥/
土壤磷素/
磷肥回收率/
磷肥利用率/
磷肥农学效率/
磷肥生理效率
Abstract:Using a long-term fertilization experiment set up in 1978 in Pingliang, Gansu Province, changes in soil phosphorus (P) and P fertilizer efficiency (PFE) were determined and used to guide rational application of P fertilizer in dry farmlands. Six fertilizer treatments-no fertilizer (CK), chemical nitrogen (N), chemical nitrogen and phosphorus (NP), straw plus chemical NP (SNP), farmyard manure (M) and farmyard manure plus chemical NP (MNP)-were used in the cropping system of 4-year continues winter wheat followed by 2-year spring corn. After 38 years, the total soil phosphorus and Olsen-P contents in CK and N treatments decreased, and phosphorus activation coefficient dropped. Total soil phosphorus contents under NP, SNP, M and MNP treatments increased respectively by 22.8%, 14.0%, 38.6% and 56.1%. Then Olsen-P contents increased respectively by 99.1%, 48.4%, 206.4% and 375.6%, while P activation coefficients were 1.7, 1.3, 2.2 and 3.1 times as that in 1978. Total soil P contents in N and SNP treatments were negatively correlated with the number of experimental years with annual decline rates of 1.9 mg·kg-1 and 2.6 mg·kg-1, respectively. Total soil P contents under NP, M and MNP treatments were positively correlated with the number of experimental years, with annual increase rates of 1.2 mg·kg-1, 1.9 mg·kg-1 and 2.8 mg·kg-1, respectively. Total soil P contents under CK remained basically unchanged with the number of experimental years. Soil available P contents under CK and N treatments decreased with increasing number of experimental years, and the annual decline rates were respectively 0.03 mg·kg-1 and 0.09 mg·kg-1. Soil available P contents under NP, SNP, M and MNP treatments were positively correlated with the number of experimental years, with annual increase rates of respectively 0.29 mg·kg-1, 0.24 mg·kg-1, 0.46 mg·kg-1 and 0.89 mg·kg-1. Crop yield was positively correlated with soil available P (wheat R2=0.116 9, n=132; corn R2=0.332 4, n=54). P using rate (PUR), P recovery rate (PRR) and P agronomic efficiency (PAE) of corn were greater than those of wheat for all 4 P treatments (NP, SNP, M and MNP), but P physiological efficiency (PPE) of wheat was greater than that of corn. The ranked order of above four indexes of P fertilizer efficiency (PFE) for different treatments was SNP > NP > MNP > M. The four indexes of PFE of maize were positively correlated with the number of experimental years. Compared with MNP treatment, P input with M decreased 14.2%. Wheat and corn PFE decreased by 14.3%-69.5% and 0.8%-75.5%, respectively. In summary, combined application of organic and inorganic fertilizers was optimal choice for improving soil fertility, increasing crop yield and enhancing resource use efficiency in Heilu soil of the Loess Plateau dryland.
Key words:Black Loessial soil/
Long-term fertilization/
Soil phosphorus/
Phosphate recovery rate/
Phosphate using rate/
Phosphorus agronomic efficiency/
Phosphate physiological efficiency
PDF全文下载地址:
http://www.ecoagri.ac.cn/article/exportPdf?id=6e48cc2b-934a-4a5d-8712-6a08b8559202
