title: [Present situation of rice fertilization in qin-ba mountainous area of Southern Shaanxi, China].
abstract: In order to understand the present situation of rice fertilization and the existing problems in the farmers' nutrient resources input in the Qin-Ba mountainous area of southern Shaanxi, the survey data from 2854 households in 11 counties of this area in the project "soil testing and formulated fertilization in 2006-2009" were analyzed and evaluated, and the countermeasures for the existing problems in the farmers' nutrient resources input were proposed. In the study area, the average rice yield was 7822 kg x hm(-2) per year, and the ratio of the households obtained the medium level yield was up to 50.9%. The input of the total fertilizers N, P2O5, K2O was 169, 68, and 54 kg x hm(-2), and the chemical fertilizer rate was 159, 62, and 45 kg x hm(-2), with the partial factor productivity (PFP) of the N, P2O5, and K2O being 51.52, 135.69, and 158.26 kg x kg(-1), respectively. According to the nutrient fertilization level, the proportion of the households fertilized with rational level of chemical N, P2O5, and K2O occupied 48.0%, 42.4%, and 7.2%, that of the households fertilized with excessive level was 22.6%, 11.2%, and 0.6%, and the proportion of the households fertilized with insufficient level occupied 29.4%, 46.5%, and 92.2%, respectively. The rice yield in the Qin-Ba mountainous area could be increased by 77 thousand tons if the households fertilizing with insufficient level of chemical NPK fertilizers increased the fertilization rate to a rational level. The existing problems in the farmers' nutrient resources input were mainly the coexistence of excessive and insufficient application of nitrogen and phosphate fertilizers and the insufficient input of potassium fertilizer and organic manure. In the rice fertilization in this area, the focus would be the balanced application of nitrogen and phosphate fertilizers, the increase of the fertilization rates of potassium fertilizer and organic manure, and the increase of top dressing, especially potassium.
authors.affiliation: College of Resources and Environmental Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China. xiaoying_shezhang@126.com
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Wang
authors.affiliation: College of Resources and Environmental Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
authors.affiliation: College of Resources and Environmental Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Yan-An
authors.initials: YA
authors.lastname: Tong
authors.affiliation: College of Resources and Environmental Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Zuo-Ping
authors.initials: ZP
authors.lastname: Zhao
mesh_terms: D000383:Agriculture / Q000379:methods*; D002681:China; D005308:Fertilizers; D009584:Nitrogen / Q000032:analysis; D012275:Oryza / Q000254:growth & development*; D010758:Phosphorus / Q000032:analysis
chemical_list: D005308:Fertilizers; D010758:Phosphorus; D009584:Nitrogen