控释尿素接触施用对番茄幼苗生长的影响

为提升蔬菜育苗的养分管理水平、培育壮苗,从而为作物高产打下基础,以不同释放期的控释尿素为试验材料,通过穴盘育苗试验研究了控释尿素与番茄种子接触施用对番茄幼苗生长的影响。结果表明：PCU50处理出现烧苗现象,番茄幼苗生长受到抑制,与常规育苗相比,株高、茎粗、叶绿素分别降低27.9%、11.1%和10.6%,地上部干重、根干重和壮苗指数则分别降低47.2%、35.6%和35.8%。而PCU130处理的番茄幼苗长势良好,茎粗、叶绿素含量和壮苗指数相比常规育苗分别增加3.70%、10.0%和35.0%,根系总吸收面积和活跃吸收面积分别增加95.1%和44.7%。控释肥与种子接触施用关键在于合理的控释肥释放期的选择,综合考虑番茄幼苗各项生长指标,认为释放期为130天的控释尿素更为适宜。     

Effect of polyolefin resin coated slow release iron fertilizer and its methods of application on rice production in calcareous soil

Experiment was carried out to evaluate the, efficiency of different iron sources including polyolefin resin coated slow release Fe fertilizer (PRCCFe) and its methods of application on the performance of rice var. Swarna during rainy seasons of 2001 and 2002 under calcareous soil at Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India. The pots were filled with 10 kg calcareous soil having high CaCO₃ (36.32%) and low iron contents (1.45 pp—less than critical limit). The experimental treatments comprised five iron sources (NPK + 100% pyrite, NPK + 100% polyolefin resin coated slow release Fe (PRCSRFe), NPK + 50% pyrite + 50% PRCSRFe, NPK + 75% pyrite + 25% PCRSRFe, and NPK + 25% pyrite + 75% PCRSRFe and two methods of application (uniform and co-situs) including one control (NPK only). These 11 treatment combinations were laid out in Completely Randomized Block Design (CRBD) replicated thrice. The two methods of iron application did not differ significantly with respect to crop yield though higher yield was recorded with co-situs application. Among the Fe sources, application of iron 75% through to + 25% through polyolefin resin coated slow release Fe fertilizer produced the highest grain yield.     

接触施用包膜控释肥对玉米产量、根系分布和土壤残留无机氮的影响

采用田间小区试验,研究了习惯施肥与接触施用包膜控释肥料对夏玉米生长、产量、根系分布和土壤无机氮残留的影响。结果表明,接触施用包膜控释肥料没有抑制玉米的出苗和幼苗生长;减氮1/3的控释肥处理(N 120kg/hm2)与习惯施肥处理(N180 kg/hm2)的玉米产量没有差异。在0—30 cm土层,与对照和习惯施肥处理相比,接触施用控释肥增加了距茎基部0—10 cm区域内玉米根长密度的分布,占总根长的59%~64%;玉米收获后,减量控释肥处理土壤剖面各个土层Nmin含量与对照相比无显著增加,习惯施肥和全量控释肥处理(N 180 kg/hm2)在60—90、90—120 cm土层的Nmin累积显著高于对照。综合考虑玉米生长、产量以及根系分布和氮素淋失风险,本试验条件下,接触施用控释肥N120 kg/hm2是夏玉米季较为理想的选择。