不同秸秆覆盖耕作方式对稻—油轮作土壤理化性状的影响

通过成都平原定位试验,进行了稻—油轮作条件下2种不同秸秆覆盖耕作方式对土壤理化性状影响的研究.结果表明:秸秆覆盖耕作对土壤全量养分、速效养分以及有机质含量均有明显的提高作用,而且均以秸秆覆盖免耕效果最好;秸秆覆盖翻耕对土壤容重与土壤孔隙度的改善作用最为明显,而秸秆覆盖免耕效果较差.作物产量分析表明,稻—油轮作条件下覆盖处理对油菜的增产效果显著,尤以免耕覆盖处理产量最高;翻耕覆盖处理对水稻上却表现为的产量最高,而免耕覆盖处理的产量最低.研究表明,在稻—油轮作条件下,如何合理地采用秸秆覆盖翻耕或秸秆覆盖免耕,是今后值得继续研究的问题.     

微囊化嗜热链球菌连续接种条件优化

为了寻求牛奶连续接种的最佳工艺,采用中心组合设计研究了牛奶连续接种各参数的不同组合对牛奶连续接种稀释率的影响,建立各参数与牛奶连续接种稀释率之间的回归模型,考查了各参数间的互作效应。获得了牛奶连续接种的最优参数组合为:连续接种温度40.9℃、pH6.8、长径比4.8。     

新疆地区滴灌小麦复播大豆施肥技术研究

在新疆地区进行滴灌小麦复播大豆栽培技术试验研究,试验年限为3年,2009年主要进行滴灌小麦复播大豆灌溉制度研究,得出最佳灌水量为3600m3·hm-2,全生育期灌水7次。2010年在此基础上进行滴灌小麦复播大豆施肥制度研究,通过对不同施肥处理生育期生长情况调查、大豆植株性状及产量调查、复播大豆成本及效益分析,总结出滴灌小麦复播大豆的施肥处理为尿素150kg+三料磷肥375kg+磷酸二氢钾225kg·hm-2时,大豆的产量最高。通过试验证明了在新疆地区进行滴灌小麦复播大豆是可行的。     

Microbial activity,organic C accumulation and <Superscript>13</Superscript>C abundance in soils under alley cropping systems after 9 years of recultivation of quaternary deposits

The impact of alley cropping on post-lignite mine soils developing from quaternary deposits after 9 years of recultivation was evaluated on the basis of microbial indicators, organic C and total N contents, and the isotope characteristics of soil C. Soils were sampled at the 0 to 3, 3 to 10, and 10 to 30 cm depths under black locust (Robinia pseudoacacia L.), poplar (Populus spp.), the transition zone and in the middle of alley under rye (Secale cereale). There was no significant effect of vegetation on microbial properties presumably, due to the high variability, whereas organic C and total N contents at the 0- to 3-cm layer were significantly higher under black locust and poplar than in the transition zone and rye field. Organic C total N contents, and basal respiration, microbial biomass, and microbial quotient decreased with soil depth. Soil organic C and total N contents were more than doubled after 9 years of recultivation, with annual C and N accretion rate of 162 g C _org m⁻² year⁻¹ and 6 g N _t m⁻² year⁻¹. Microbial properties indicated that the soils are in early stages of development; the C isotope characteristics confirmed that the sequestered C was predominantly from C3 plants of the alley cropping.     

红壤旱地不同玉米种植系统的生态学功能评价

为了充分发挥红壤旱地的生态功能,筛选出较优化的玉米种植系统,本研究依据近23 a (1984～2006)的田间试验资料,从农田生态系统的生产功能、能流功能、价值流功能以及用养结合功能等四个方面对红壤旱地15种玉米种植系统进行了分析,并采用灰色关联度法从生态效益、经济效益和社会效益三个层次13个指标对各种植模式进行综合评价,筛选出了3种适宜于在红壤旱地上推广的较优化的玉米种植系统。结果表明,处理(10)"豌豆/早玉米+旱稻/晚玉米"的社会效益和生态效益关联度值分别为0.750和0.986,均居第一位,其经济效益关联度值为0.841,居第二位,经灰色关联度分析,得出其综合加权关联度值最大,是最适宜在南方红壤旱地上推广的优化种植模式。处理(12)"紫云英—早玉米—芝麻"和处理(11)"豌豆/棉花+早玉米"的加权关联度值也较大,分别为0.739和0.716,居第二位和第三位,这两种种植模式对今后红壤旱作区种植业结构布局和种植方式的优化具有积极意义。     

Combining chlorophyll meter readings and high spatial resolution remote sensing images for in-season site-specific nitrogen management of corn

The chlorophyll meter (CM) has been commonly used for in-season nitrogen (N) management of corn (Zea mays L.). Nevertheless, it has limited potential for site-specific N management in large fields due to difficulties in using it to generate N status maps. The objective of this study was to determine how well CM readings can be estimated using aerial hyper-spectral and simulated multi-spectral remote sensing images at different corn growth stages. Two field experiments were conducted in Minnesota, USA during 2005 involving different N application rates and timings on a corn-soybean [Glycine max (L.) Merr.] rotation field and a corn-corn rotation field. Four flights were made during the growing season using the AISA Eagle Hyper-spectral Imager and CM readings were collected at four or five different growth stages. The results indicated that single multi-spectral and hyper-spectral band or vegetation index could explain 64–86% and 73–88% of the variability in CM readings, respectively, except at growth stage V9 in the corn-soybean rotation field where no band or vegetation index could explain more than 37% of the variability in CM readings. Multiple regression analysis demonstrated that the combination of 2–4 broad-bands or 3–8 narrow-bands could explain 41–92% or 61–94% of the variability in CM readings across the two fields and different corn growth stages investigated. It was concluded that the combination of CM readings with high spatial resolution hyper-spectral or multi-spectral remote sensing images can overcome the limitations of using them individually, thus offering a practical solution to N deficiency detection and possibly in-season site-specific N management in large continuous corn fields or at later stages in corn-soybean rotation fields.     

An Evaluation of the Introduction of Modified Cropping Practices in Yunnan Province, China, Using Surveys of Farmers＇ Households

Problems associated with land degradation are serious in China. Sloping land in South China has experienced a decline in crop productivity by 30-60% due to soil erosion and it has been predicted that most topsoil will be lost within the next 100 years if current erosion rates continue. Considering these situations, an agro-environmental research and development project （Sustainable Highland Agriculture in South-East Asia- SHASEA） was conducted in a catchment in Yunnan Province, China, to address the objectives of increasing crop productivity in sustainable and environmentally-friendly ways. A range of cropping practices was developed and implemented in a rural upland catchment （Wang Jia）. At the end of the project, farmers were surveyed to evaluate project effectiveness. All farmers from Wang Jia Catchment, who were involved in project implementation, were surveyed. A sample of farmers working in an adjacent catchment （not associated with the project） was surveyed for comparative purposes. Farmers had different perceptions of the cropping practices employed. Contour cultivation was preferred and likely to be adopted. Others practices such as straw mulching and intercropping were seen as less appropriate and unlikely to be adopted. Polythene mulch was recognized as effective, but likely to be adopted only if financial returns were favourable. The availability of relevant information had an important impact on the extent of technology testing by farmers and their willingness to adopt the practices in the future.     

“甜瓜——粳稻——蔬菜”高产高效栽培技术

近年来南京市浦口区积极推进稻田种植制度创新,示范推广了"水稻+N"新型高效种植模式,对建设资源节约型社会、推进种植业高效规模化、增加农民收入、建设生态农业、改良土壤和减轻农作物病虫害的发生十分有利.其中"甜瓜--粳稻--蔬菜"种植模式在乌江镇示范推广较快,2008年种植面积70 hm2,一般纯收入5.85万元/hm2.文中从茬口安排、品种选用和栽培技术要点等方面论述了该模式的高产高效栽培技术.     

强化栽培稻田主要病虫害的发生规律研究

研究了强化栽培单季稻稻田生态系统中水稻主要病虫的发生规律及使用农药防治靶标病虫时对非靶标病虫的影响。结果表明,强化栽培方式下褐飞虱种群数量较常规栽培方式增加了21.47%,白背飞虱增加了27.19%,稻纵卷叶螟增加了57.95%,二化螟增加了200.0%,纹枯病病情指数增加了29.10%。防治病虫靶标对非靶标病虫种群发展的影响以稻飞虱最为突出,用杀虫双、茚虫威、井冈霉素和苯甲·丙环唑等药剂防治螟虫、稻纵卷叶螟和纹枯病等靶标病虫时,均会刺激褐飞虱和白背飞虱种群数量增殖,其增殖幅度较常规栽培方式提高了26%～60%。     

免耕抛栽水稻的根系特性初步研究

通过2005—2007年连续3 a定位试验,在双季稻田研究了免耕抛秧水稻的根系特性。结果表明：免耕抛秧水稻根系干重低于翻耕移栽稻,根系大部分分布在表层（0-5 cm土层）土壤。水稻单穴根系固持力表现为翻耕移栽〉翻耕抛秧〉免耕抛秧,且随着免耕年限的延长,这种趋势更明显。