title: Ammonia volatilization from urea-application influenced germination and early seedling growth of dry direct-seeded rice.
abstract: Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding.
authors.affiliation: Crop Physiology and Production Center, National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Hubei, Wuhan 430070, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Qi
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Farooq
authors.initials: F
authors.lastname: Shah
authors.forename: Shaobing
authors.initials: S
authors.lastname: Peng
authors.forename: Jianliang
authors.initials: J
authors.lastname: Huang
authors.forename: Kehui
authors.initials: K
authors.lastname: Cui
authors.forename: Hongyan
authors.initials: H
authors.lastname: Liu
authors.forename: Lixiao
authors.initials: L
authors.lastname: Nie
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D018525:Germination / Q000187:drug effects*; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D014508:Urea / Q000494:pharmacology*; D014835:Volatilization
chemical_list: D000641:Ammonia; D014508:Urea