title: Highly Arid Oasis Yield, Soil Mineral N Accumulation and N Balance in a Wheat-Cotton Rotation with Drip Irrigation and Mulching Film Management.
abstract: Few systematic studies have been carried out on integrated N balance in extremely arid oasis agricultural areas. A two-year field experiment was conducted to evaluate the N input and output balances under long-term fertilization conditions. Five treatments were chosen, namely CK (no fertilizer), NPK, NPKS (10% straw return N and 90% chemical N), NPKM (one third urea-N, two thirds sheep manure) and NPKM+ (1.5 times NPKM). The results show an abundance of dry and wet N deposition (33 kg N ha-1 yr-1) in this area. All treatments (excluding CK) showed no significant difference in wheat production (P>0.05). NPKM gave higher cotton yields (P<0.05). In both crops, NPKM and NPKS treatments had a relatively higher N harvest index (NHI). 15N-labeled results reveal that the fertilizer N in all N treatments leached to<1 m depth and a high proportion of fertilizer-N remained in the top 60 cm of the soil profile. The NPKM+ treatment had the highest residual soil mineral N (Nmin, 558 kg Nd ha-1), and NPKM and NPKS treatments had relatively low soil Nmin values (275 and 293 kg N ha-1, respectively). Most of the treatments exhibited very high apparent N losses, especially the NPKM+ treatment (369kg N ha-1). Our arid research area had a strikingly high N loss compared to less arid agricultural areas. Nitrogen inputs therefore need careful reconsideration, especially the initial soil Nmin, fertilizer N inputs, dry and wet deposition, and appropriate organic and straw inputs which are all factors that must be taken into account under very arid conditions.
authors: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.|Institute of Plant Nutrition, Resources and Environmental Sciences, Henan Academy of Agricultural Sciences, Zhengzhou, China.
authors: Jinling
authors: J
authors: Lv
authors: Soil and Fertilizer Institute, Xinjiang Academy of Agricultural Sciences, Urumqi 830000, China.
authors: Hua
authors: H
authors: Liu
authors: Soil and Fertilizer Institute, Xinjiang Academy of Agricultural Sciences, Urumqi 830000, China.
authors: Xihe
authors: X
authors: Wang
authors: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Kaihui
authors: K
authors: Li
authors: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Changyan
authors: C
authors: Tian
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
authors: Xuejun
authors: X
authors: Liu
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D000383:Agriculture / Q000379:methods*; D000388:Air; D064751:Ammonium Compounds / Q000032:analysis; D000818:Animals; D002681:China; D018556:Crops, Agricultural / Q000254:growth & development; D003889:Desert Climate; D004777:Environment; D005308:Fertilizers / Q000032:analysis; D003368:Gossypium / Q000254:growth & development*; D008372:Manure / Q000032:analysis; D008903:Minerals / Q000032:analysis*; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D009587:Nitrogen Isotopes; D011891:Rain; D012399:Rotation; D012621:Seasons; D012756:Sheep; D012987:Soil / Q000737:chemistry*; D013696:Temperature; D014908:Triticum / Q000254:growth & development*
chemical_list: D064751:Ammonium Compounds; D005308:Fertilizers; D008372:Manure; D008903:Minerals; D009566:Nitrates; D009587:Nitrogen Isotopes; D012987:Soil; D009584:Nitrogen