Manure and nitrogen application enhances soil phosphorus mobility in calcareous soil in greenhouses.
Over many years, high phosphorus (P) loading for intensive vegetable cropping in greenhouses of North China has contributed to excessive P accumulation, resulting in environmental risk. In this study, the influences of manure and nitrogen (N) application on the transformation and transport of soil P were investigated after nine years in a greenhouse tomato double cropping system (winter-spring and autumn-winter seasons). High loading of manure significantly increased the soil inorganic P (Pi), inositol hexakisphosphate (IHP), mobile P and P saturation ratio (PSR, >0.7 in 0-30 cm depth soil; PSR was estimated from P/(Fe + Al) in an oxalate extract of the soil). The high rate of N fertilizer application to the studied calcareous soil with heavy loading of manure increased the following: (i) mobile organic P (Po) and Pi fractions, as evidenced by the decrease in the ratio of monoesters to diesters and the proportion of stable Pi (i.e., HCl-Pi) in total P (Pt) in 0-30 cm depth soil; (ii) relative distribution of Po in the subsoil layer; and (iii) P leaching to soil depths below 90 cm and the proportion of Po in Pt in the leachate. More acidic soil due to excessive N application increased P mobility and leaching. The increase in Ox-Al (oxalate-extractable Al) and the proportion of microbe-associated Po related to N application at soil depths of 0-30 cm suggested decrease in the net Po mineralization, which may contribute to downward transport of Po in the soil profile.
College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing 100193, PR China.
Zhengjuan
Z
Yan
College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing 100193, PR China.
Shuo
S
Chen
College of Resources and Environmental Sciences, Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao 266109, PR China.
Junliang
J
Li
United States Department of Agriculture-Agricultural Research Service, Agricultural Systems Research Unit, 1500 N. Central Ave, Sidney, MT 59270, USA.
Ashok
A
Alva
College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing 100193, PR China. Electronic address: qchen@cau.edu.cn.
Qing
Q
Chen
D002681:China; D018556:Crops, Agricultural; D006801:Humans; D008372:Manure; D009584:Nitrogen / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D014675:Vegetables
D008372:Manure; D012987:Soil; D010758:Phosphorus; D009584:Nitrogen
Leachate; Manure incorporation; Nitrogen fertilization; Organic P; P fractionation; Soil acidification