title: [Effects of long-term applying sulfur- and chloride-containing chemical fertilizers on weed growth in paddy field].
abstract: An investigation was made at a double-rice paddy field in the Qiyang Red Soil Field Experimental Station, Hunan Province, China to study the species and biomass of weeds growing in rice (Oryza sativa L.) growth season after 34-year application of sulfur (SO4(2-)) and chloride (Cl(-))-containing chemical fertilizers under the same application rates of nitrogen (N), phosphorus (P), and potassium (K). Long-term application of Cl(-)-containing chemical fertilizer resulted in the greatest species number of weeds and the highest biomass of floating weeds and wet weeds, compared with long-term application of SO4(2-) and Cl(-) +SO4(2-)-containing chemical fertilizers. In early rice growth season, the biomass of weeds after applying Cl(-)-containing chemical fertilizer was 51.4% and 17.6% higher than that after applying Cl(-) + SO4(2-) and SO4(2-)-containing chemical fertilizers, respectively; in late rice growth season, the increment was 144% and 242%, respectively. More floating weeds were observed after applying Cl(-) + SO4(2-) and SO4(2-)-containing chemical fertilizers, but few of them were found after applying Cl(-)-containing chemical fertilizer. The total dry mass of weeds and the dry mass of wet weeds were positively correlated with soil Cl(-) content (r = 0.764, P < 0.01 and r = 0.948, P < 0.01, respectively), but negatively correlated with soil SO4(2-)-S content (r = 0.849, P < 0.01 and r = 0.641, P < 0.05). Soil alkali-hydrolyzable N and available P, under the co-effects of soil SO4(2-)-S, Cl(-), and pH, had indirect effects on the total dry mass of weeds. By adopting various fertilization measures to maintain proper soil pH and alkali-hydrolyzable N and available P contents, increase soil SO42(-)-S content, and decrease soil Cl(-) content, it could be possible to effectively inhibit the growth of wet weeds and to decrease the total biomass of weeds in double-rice paddy field.
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Beijing 100081, China. shenpuych@163.com
authors.forename: Pu
authors.initials: P
authors.lastname: Shen
authors.forename: Ju-sheng
authors.initials: JS
authors.lastname: Gao
authors.forename: Ming-gang
authors.initials: MG
authors.lastname: Xu
authors.forename: Dong-chu
authors.initials: DC
authors.lastname: Li
authors.forename: De-kui
authors.initials: DK
authors.lastname: Niu
authors.forename: Dao-zhu
authors.initials: DZ
authors.lastname: Qin
mesh_terms: D002681:China; D002712:Chlorides / Q000494:pharmacology*; D017753:Ecosystem; D005308:Fertilizers; D009584:Nitrogen / Q000494:pharmacology; D012275:Oryza / Q000254:growth & development*; D010758:Phosphorus / Q000494:pharmacology; D057685:Plant Weeds / Q000254:growth & development*; D006109:Poaceae / Q000254:growth & development*; D013455:Sulfur / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D002712:Chlorides; D005308:Fertilizers; D010758:Phosphorus; D013455:Sulfur; D009584:Nitrogen