title: Analysis of water and nitrogen use efficiency for maize (Zea mays L.) grown on soft rock and sand compound soil.
abstract: BACKGROUND
  Maize was grown on compound soils constituted from mixtures of soft rock and sand at different ratios, and water use efficiency (WUE), nitrogen use efficiency (NUE) and fertilizer nitrogen use efficiency (FNUE) were quantified. The data were used to assist in designing strategies for optimizing water and nitrogen management practices for maize on the substrates used. Maize was sown in composite soil prepared at three ratios of soft rock and sand (1:1, 1:2 and 1:5 v/v) in Mu Us Sandy Land, Yuyang district, Yulin city, China. Yields, amount of drainage, nitrogen (N) leaching, WUE and NUE were calculated. Then a water and nitrogen management model (WNMM) was calibrated and validated.
  
  
  RESULTS
  No significant difference in evapotranspiration of maize was found among compound soils with soft rock/sand ratios of 1:1, 1:2 and 1:5, while water drainage increased significantly with increasing soft rock/sand ratio. WUE increased to 1.30 kg m-3in compound soil with 1:2 soft rock/sand ratio. Nitrogen leaching and ammonia volatilization were the main reason for nitrogen loss, and N reduction mainly relied on crop uptake. NUE and FNUE could reach 33.1 and 24.9 kg kg-1N respectively. Water drainage and nitrogen leaching occurred mostly during heavy rainfall or irrigation. Through a scenario analysis of different rainfall types, water and fertilizer management systems were formulated each year.
  
  
  CONCLUSIONS
  This study shows that soft rock plays a key role in improving the WUE, NUE and FNUE of maize. © 2016 Society of Chemical Industry.
authors.affiliation: Shaanxi Provincial Land Engineering Construction Group Co., Ltd, ShaanXi Province Land Reclamation Engineering Technology Research Center, Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Land and Resources of China, Xi'an, Shaanxi, 710075, China.
authors.forename: Huanyuan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Shaanxi Provincial Land Engineering Construction Group Co., Ltd, ShaanXi Province Land Reclamation Engineering Technology Research Center, Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Land and Resources of China, Xi'an, Shaanxi, 710075, China.
authors.forename: Jichang
authors.initials: J
authors.lastname: Han
authors.affiliation: Shaanxi Provincial Land Engineering Construction Group Co., Ltd, ShaanXi Province Land Reclamation Engineering Technology Research Center, Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Land and Resources of China, Xi'an, Shaanxi, 710075, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tong
authors.affiliation: Shaanxi Provincial Land Engineering Construction Group Co., Ltd, ShaanXi Province Land Reclamation Engineering Technology Research Center, Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Land and Resources of China, Xi'an, Shaanxi, 710075, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Shaanxi Provincial Land Engineering Construction Group Co., Ltd, ShaanXi Province Land Reclamation Engineering Technology Research Center, Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Land and Resources of China, Xi'an, Shaanxi, 710075, China.
authors.forename: Haiou
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000383:Agriculture; D002681:China; D005308:Fertilizers / Q000032:analysis; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000032:analysis / Q000378:metabolism*; D003313:Zea mays / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D012987:Soil; D014867:Water; D009584:Nitrogen
keywords: drainage; nitrogen leaching; sandy soil; soft rock; water and nitrogen management model; water and nitrogen use efficiencies