稻田田埂植物的生物多样性

 在浙江安吉两个村对利用不同污染程度水源进行灌溉的稻田田埂植物进行了调查。利用未受工业污染的水灌溉的禹山坞稻田田埂植物种数高于受工业废水污染的城北村。在相同类型植物群落中, 禹山坞稻田田埂的植物种总重要值Iv(t)显著高于城北村,两村的田埂植物生物多样性指数也存在类似的变化趋势。不同类型植物群落的生物多样性参数差异极为显著, 矮秆植物占优势群落的植物种数、植物种总重要值和生物多样性指数(H')显著高于高秆植物占优势群落和外来植物占优势群落。应重视防除外来植物空心莲子草, 控制高秆植物和保护矮秆植物。     

化学除草剂污染的分析与治理

大部分化学除草剂在施用后会残留下来,对环境造成污染。可通过进行除草剂残留量预测,推广使用毒性较低的土壤处理剂来减少土壤中化学除草剂的残留量,使用各种物质减轻土壤中残留化学除草剂对作物的危害,加强植物修复技术和微生物降解技术的应用等来治理对土壤的污染;使用对大气污染轻的除草剂剂型等来减轻对大气的污染;通过保护水源,防止稻田化学除草剂流失等来减少对水环境的污染。     

云南三种野生稻原生境植物种群的调查及比较分析

对云南省境内的3种野生稻40个原生境的植物群落进行了考察,共记录植物159种,分属于51科。按乔木层、灌木层、草本层对野生稻原生境植物种类进行分类,乔木层植物共6科1亚科11种,灌木层植物共29科60种,草本层植物共20科88种;普通野生稻原生境的植物种类95%为草本层,疣粒野生稻的植物则有明显的垂直层次结构。普通野生稻原生境植物共计20种,均为特有植物种,分属于5科,主要为禾本科和莎草科;药用野生稻原生境植物共计25种,分属于19个科,特有种15个;疣粒野生稻原生境植物共计125种,分属于45科,特有植物种数达117个。最后就3种野生稻原生境植物种类调查的意义、外来物种对野生稻的原生境威胁等问题进行了讨论。     

“丁滴”防除稻田杂草效果与产量效应初报

丁草胺是近几年大面积应用的优良稻田除草剂。但是,由于该药杀草谱的局限,不少稻田在多年使用之后,一些双子叶杂草如矮慈菇、鸭舌草、田蓼等成为稻田新的优势草种。为了解决稻田杂草群落新变化,引进了广州农药厂生产的35％丁滴乳油新的内吸性复配合剂,进行了杀草谱、有效剂量及对水稻生育与产量影响的试验、示范。试验表明,35％丁滴乳油对稻田杂草防除效果和对水稻安全性较之以往推广的除草剂有明显提高,尤其杀草谱比丁草胺草剂有明显扩大。在亩施75毫升、100毫升、125毫     

稻田除草剂应用现状与抗除草剂水稻育种研究进展

在水稻生产中，杂草是影响稻谷产量和品质的主要原因之一，而除草剂是目前最有效的除草手段。近年来，市场供应的稻田除草剂商品种类庞杂，常用除草剂使用量逐年增加，单一除草剂长期大量使用带来的杂草抗药性问题和除草剂残留引起的食品安全、农田生态环境问题日益严重，难以有效解决。创制抗除草剂水稻品种是解决稻田杂草危害重、防控难的一种较好选择。本文从稻田杂草及其发生规律入手，介绍了水稻直播和移栽种植模式下杂草的治理措施、稻田常用除草剂应用现状及挑战，重点研究了最新的抗除草剂水稻新品种育种进展和应用情况，展望了生物育种技术在抗除草剂水稻创制中的发展前景，旨在为提高稻田杂草防控水平，促进抗除草剂水稻育种研究和扩展生物育种技术应用范围提供参考。     

稻田土壤矿化N季节性变化和因子控制

为了阐明矿化N素因子调控原理,作者探讨了稻作期间稻田土N素矿化随季节和土层变化的情况。采集表层土壤为样品,以周围海湾水为灌溉水,稻田中央被富营养化灌溉水所污染,这些土壤分为顶层表土(0—3cm)和3—9cm2层,土样分析项目是是在30℃下恒温培养4周后的干、湿土壤的矿化N量,土壤酶活性(包括β—葡萄糖酶,β—乙酰基葡萄糖胺酶,蛋白酶),碳水化合物全量,可溶热水的已糖和NH_3-N。夏季土壤N素矿化的风干效应十分明显,复水后有利于水稻生长。与     

江苏“水稻-小龙虾”综合种养稻田杂草群落及其防控技术调查：以12个基地为例

为揭示江苏“水稻-小龙虾”综合种养稻田杂草群落结构和农户杂草防控措施现状,对灌南、盐都、盱眙、高邮、广陵、溧阳、常熟等7个地方12个稻虾综合种养基地开展田间调查和农户访谈。结果表明,在120块稻虾田内共记录到25种杂草;稻虾轮作田禾本科杂草和千金子的优势度显著高于稻虾共生田。稻虾轮作稻田杂草以稗属杂草、杂草稻、千金子、李氏禾、异型莎草、水苋菜属杂草、鸭舌草为主;稻虾共生稻田杂草以杂草稻、稗属杂草、千金子、异型莎草为主。除有机栽培模式外,稻虾轮作稻田控草方式为“土壤处理+茎叶处理+人工拔除”,稻田杂草防控总用药和人工成本平均1 863.75元/hm²。稻虾共生稻田控草技术主要为“水层控草+龙虾控草+人工拔除”,部分稻田使用丙草胺、苄嘧磺隆等土壤处理除草剂,稻田杂草防控总成本平均907.50元/hm²。     

稻田养蟹绿色生产技术规程

为合理有效利用土地、灌溉水、温光等资源,提高水稻、河蟹的产量及品质,减少化肥农药对稻谷、河蟹及周边环境的污染,按照绿色食品生产的相关规定,结合辽宁滨海稻区稻田养蟹的现状,在深入调研及专家组评审的基础上,制定了《稻田养蟹绿色生产技术规程》。从前期准备、工程建设、水稻生产技术、河蟹养殖技术等方面提出了稻田养蟹的相关要求。     

植物源农药在水稻上的应用现状与展望

主要从植物源农药作为杀虫剂、杀菌剂、除草剂在水稻生产中的应用现状及有效物质对水稻病虫草害的作用方式进行了较全面的论述。经过多年的研究表明:植物源药剂与环境有很好的相容性,对稻田天敌、水生动物安全,且能促进水稻生长,提高产量。因此,深入研究植物源农药对水稻病虫草害的作用效果、应用技术以及在稻田的综合利用,对推动我国无公害水稻生产具有巨大的现实意义。     

浅谈稻田生态养鱼技术

稻田养鱼技术可以减少水稻种植过程中除草剂、杀虫剂和化肥的使用,达到降低成本、减少污染的效果,是一套高产、优质、低耗、高效的水生农业生态体系。在稻、鱼共生系统中探索生态种养技术,把种植业和养殖业有机结合起来,实现水稻的有机生产。从稻田条件、鱼种选择、养鱼设施建设和生产管理等方面介绍了稻田养鱼技术,以指导稻田生态养殖的推广。     

Model development for surface drainage loading estimates from paddy rice fields

A field experiment was performed at two Korean research sites to evaluate water and nutrient behavior in paddy rice culture operations for 2 years. One site was irrigated with groundwater, whereas the other site was irrigated with surface water. Both sites received average annual rainfall of about 1,300 mm, and about 70–80% of it was concentrated during July–September coinciding with rice growing season. Although most of the nutrient outflow was attributed to plant uptake, nutrient loss by surface drainage was substantial. The simplified computer model, PADDIMOD, was developed to simulate water and nutrient behaviors in the paddy rice field. The model predicts daily ponded water depth, surface drainage, and nutrient concentrations. It was formulated with a few equations and simplified assumptions, but its application and a model fitness test indicated that the simulation results reasonably matched the observed data. It is a simple and practical planning model that could be used to evaluate nutrient loading from paddy rice fields alone or in combination with other complex watershed models. Further validation might be required for general application of the PADDIMOD to the simulation of paddy rice fields with various agricultural environments.     

沪优2号望天田高产栽培技术

沪优2号由上海市农业生物基因中心选育,2010年通过国家品种审定,具有株型好、抗倒、抗旱、耐肥、耐高温、结实率高、米质优、穗足产量高的特点,不但可以在建瓯市水田大面积推广,还是缺水的望天田种植水稻的首选品种。     

四川丘陵季节性干旱区水稻田间耗水量研究

以Ⅱ优7号为供试水稻品种,通过精确计量稻田进出水量,研究了四川典型丘陵地区稻田耗水量.结果表明,丘陵地区降水利用率为71.59％,但降水与稻田需水不完全同步;全生育期总灌水量为6 298.6 m3/hm2;稻田耗水量为8 884.4 m3/hm2.相关分析表明,稻田耗水量与稻谷产量呈显著正相关.在四川丘陵地区水稻生产中,节水仍有一定空间.     

乙氧氟草醚在水稻及其生态环境中的残留降解动态

乙氧氟草醚在水稻及其生态环境中的残留降解动态楼小华，梁天锡，吴园生，平霄飞（中国水稻研究所杭州３１０００６）关键词乙氧氟草醚，残留降解，最终残留ＤｅｇｒａｄａｔｉｏｎＤｙｎａｍｉｃｓｏｆＯｘｙｆｌｕｏｒｆｅｎｉｎＲｉｃｅａｎｄＩｔｓＥｃｏｓｙｓｔｅｍ...     

More Rice,Less Water—Integrated Approaches for Increasing Water Productivity in Irrigated Rice-Based Systems in Asia

Abstract

The water crisis is threatening the sustainability of the irrigated rice system and food security in Asia. Our challenge is to develop novel technologies and production systems that allow rice production to be maintained or increased in the face of declining water availability. This paper introduces principles that govern technologies and systems for reducing water inputs and increasing water productivity, and assesses the opportunities of such technologies and systems at spatial scale levels from plant to field, to irrigation system, and to agro-ecological zones. We concluded that, while increasing the productivity of irrigated rice with transpired water may require breakthroughs in breeding, many technologies can reduce water inputs at the field level and increase field-level water productivity with respect to irrigation and total water inputs. Most of them, however, come at the cost of decreased yield. More rice with less water can only be achieved when water management is integrated with (i) germplasm selection and other crop and resource management practices to increase yield, and (ii) system-level management such that the water saved at the field level is used more effectively to irrigate previously un-irrigated or low-productivity lands. The amount of water that can be saved at the system level could be far less than assumed from computations of field-level water savings because there is already a high degree of recycling and conjunctive use of water in many rice areas. The impact of reducing water inputs for rice production on weeds, nutrients, sustainability, and environmental services of rice ecosystems warrants further investigation.     

稻蟹共作模式生态效应研究进展

主要从土壤、水环境和杂草防控三个方面,对目前我国稻蟹共作模式下田间生态的研究现状进行了总结与分析.提出了几种目前比较常见的稻蟹共作模式,即有机稻蟹和常规稻蟹两种普遍模式.分析了稻蟹共作对土壤理化性质、土壤酶活性和根际微生物区系的影响.养蟹稻田可以显著降低土壤容重,而总孔隙度及全氮、全磷、碱解氮、有效磷、速效钾和土壤有机质含量都显著增加;显著提高0~10 cm土壤脲酶、蛋白酶、脱氢酶以及过氧化氢酶的活性;土壤根际微生物以细菌为主要菌群,氨化细菌、反硝化细菌、嫌气性纤维素分解菌、好气性自生固氮菌、亚硝酸细菌数量显著高于单作水稻;与常规稻蟹相比,有机稻蟹的土壤性状表现更好.稻蟹模式下浮游动植物的多样性和生物量显著低于单作水稻,而水体中溶解氧(DO)明显偏低,硝酸盐、磷酸盐含量显著高于不养蟹稻田.稻田养蟹能够显著抑制稻田4种优势杂草的密度,对于稻田杂草的防控效果明显.     

水分管理调控水稻镉污染的研究与应用进展

我国稻田镉污染严重,稻米安全问题突出,发展能够有效调控水稻镉污染的产品与措施尤为迫切。稻田生态系统高度复杂,并易受多种因素影响,水稻镉污染调控难度大。大量研究表明,合理的水分管理不仅能够保障水稻正常的生长发育、产量和稻米品质,同时还能有效减少水稻镉积累。本文综述了水分对土壤理化性质、微生物动态变化以及植物生长发育的影响,阐述了水分管理降低水稻镉积累的主要机理,总结和展望了目前水分管理模式相关研究进展以及未来研究方向,旨在为实际生产上通过优化水分管理技术降低镉污染提供理论依据,更有效实现水稻安全生产。     

A quick determination of root resistance to water transport in paddy rice

Hydraulic resistance in plants is one of the most important factors responsible for changes in leaf water potential that is an indicator of plant water stress. Although the hydraulic resistance to passive water transport (R_pa) is a robust index in paddy rice (Oryza sativa), measurement is both time-consuming and labour-intensive. Here, we describe on a quick method to measure hydraulic resistance to osmotic water transport (R_os) by measuring the xylem sap exudation rate and osmotic water potential. In a greenhouse experiment, R_os responded significantly to soil temperature, but under field conditions soil temperature varied considerably less than air temperature. In the field experiment, R_os of six rice cultivars at two growth stages was strongly positively correlated with R_pa. We conclude that measuring R_os could be used to evaluate root water transport capacity in paddy rice under conditions with adequate soil water.     

Quantitative risk assessment for reclaimed wastewater irrigation on paddy rice field in Korea

Water shortage has become an important issue for Korean agriculture. Korea suffers from a limited agricultural water supply, and wastewater reuse has been recommended as an alternative solution. This study examined the concentrations of toxic heavy metals and Escherichia coli in a paddy rice field irrigated with reclaimed wastewater to evaluate the risk to farmers. Most epidemiological studies have been based on upland fields, and therefore may not be directly applicable to paddy fields. In this study, a Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion. The risk value increased significantly after irrigation and precipitation. The results of the microbial risk assessment showed that risk values of groundwater and reclaimed wastewater irrigation were lower than the values of effluent directly from wastewater treatment plants. The monitoring results of heavy metals for each irrigated paddy fields did not show specific tendency. A risk assessment for toxic heavy metals was performed according to various exposure pathways; however, the results of the carcinogenic and noncarcinogenic risk estimation showed that the risk from reclaimed wastewater-irrigated paddy fields was the lowest.