title: [Effects of long-term application of organic fertilizer and superphosphate on accumulation and leaching of Olsen-P in Fluvo-aquic soil].
abstract: Based on a 20-year experiment of fertilization with organic and chemical fertilizers on a Fluvo-aquic soil under wheat-corn cropping system, this paper studied the relationships between Olsen-P concentration in plough layer and crop yields as well as the accumulation and vertical translocation of Olsen-P in soil profile. The results showed that when the Olsen-P concentration in plough layer maintained at 10-40 mg x kg(-1), the grain yields of wheat and corn were higher, whereas when the concentration of Olsen-P in plough layer was higher than 40 mg x kg(-1), it started to leach, which meant that in light loam Fluvo-aquic soil, the threshold value for P leaching might be 40 mg x kg(-1). In the treatments of chemical fertilization (NPK) and corn straw returning (SNPK) with the P application rate of 77-90 kg x hm(-2), the Olsen-P concentration in plough layer was increased by 0.63-0.72 mg x kg(-1) per 100 kg x hm(-2) of applied P, with an annual increment of 0.49-0.65 mg x kg(-1) and needed 45-60 years for reaching the threshold value for P leaching. In the treatments of chemical fertilization combined with manure application (MNPK, MNPK2, and 1.5MNPK), the formula of Olsen-P accumulation in 0-20 cm soil layer were Y(MNPK) = 3.1097x + 6.9615 (R2 = 0.8562), Y(MNPK2) = 2.4765x + 13.563 (R2 = 0.9307), and Y1.5MNPK = 4.506x + 6.4464 (R2 = 0.8862). It might take 8 years to reach the threshold value for Olsen-P leaching when the P application rate in treatment 1.5MNPK was 210 kg x hm(-2), 11 years when the P application rate in treatments MNPK2 and MNPK was 125 and 140 kg x hm(-2). Organic fertilization combined with chemical fertilization increased the Olsen-P accumulation rate being 2.5 times higher than chemical fertilization. Excessive application of organic fertilizer could increase the accumulation and leaching of Olsen-P in soil profile.
authors.affiliation: Institute of Plant Nutrition and Resources Environment, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China. hsm503@126.com
authors.forename: Shao-Min
authors.initials: SM
authors.lastname: Huang
authors.forename: Dou-Dou
authors.initials: DD
authors.lastname: Guo
authors.forename: Shui-Qing
authors.initials: SQ
authors.lastname: Zhang
mesh_terms: D000383:Agriculture / Q000379:methods*; D018556:Crops, Agricultural / Q000254:growth & development* / Q000378:metabolism; D011756:Diphosphates / Q000737:chemistry*; D005308:Fertilizers; D008372:Manure; D009930:Organic Chemicals / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D013997:Time Factors; D014908:Triticum / Q000254:growth & development / Q000378:metabolism; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism
chemical_list: D011756:Diphosphates; D005308:Fertilizers; D008372:Manure; D009930:Organic Chemicals; D012987:Soil; D010758:Phosphorus; C033414:superphosphate