Contingent valuation approach in measuring the multifunctionality of agriculture and rural areas in Japan

The purpose of this study was to measure the economic value of the multifunctionality of agriculture and rural areas based on a more realistic assumption than that adopted in previous studies. Willingness to pay (WTP) for implementing a policy that would maintain a level of multifunctionality corresponding to a 20% decrease in the farmland area in Japan was measured by the double-bounded dichotomous choice contingent valuation method (CVM). According to a country-wide survey, the overall median WTP was 4,144 yen per household annually. The multifunctionality of agriculture and rural areas was classified into eight functions. The WTP for each of these functions was calculated taking into account the ratings assigned to the functions by the respondents. The WTP was 649 yen for flood prevention, 505 yen for recharging groundwater, 642 yen for water environment conservation, 445 yen for soil erosion prevention, 579 yen for organic resource utilization, 394 yen for the development of favorable landscapes, 290 yen for recreation and relaxation, and 641 yen for wildlife protection.     

农得时活性与在稻田中降解动态的研究

The activity and kinetics of Londax in the paddy field were presented in this paper. The degradation of Londax was fast at initial period. The half-time were about 3-5 days and 11-15 days in water and soil respectively. Activity of Londax were increased with increasing pH and temperature of water. Activity of Londax varied in different water resources, the sequence of activity of Londax were in underground water>river water>distilled water.     

农得时活性与在稻田中降解动态的研究

农得时活性与在稻田中降解动态的研究陶波，苏少泉（东北农业大学农学系，哈尔滨１５００３０）ＡｃｔｉｖｉｔｙａｎｄＤｅｇｒａｄａｔｉｏｎｏｆＬｏｎｄａｘｉｎＰａｄｄｙＦｉｅｌｄ￥ＴＡＯＢｏ；ＳｕＳｈａｏｑｕａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＡｇｒｏｎｏｍｙ，...     

水稻水田旱整与常规水整栽培技术比较研究

为研究水田旱整栽培技术的优缺点,以99-25为试验材料,分析水田旱整和常规水整2种栽培方式下植株的形态特征、土壤的理化性状和水稻产量及其构成因素等。结果表明:与常规水整相比,水田旱整能明显提高水稻植株的生物量,降低土壤含水量、氯离子含量、速效钾含量和pH值等,从而改善土壤理化性状,提高下茬作物的播种质量。但是,水田旱整栽培方式下的水稻产量却有所降低,但减产不显著。     

水稻机插秧田间杂草发生规律及防控研究

机插秧水稻大面积推广的关键障碍因子之一是杂草防控,其防控技术与普通移栽稻有所不同。为了真实了解田间杂草发生规律,指导农户科学防控,笔者在洞庭湖双季稻区,运用田间试验的方式,安排了4种不同化学除草剂组合防控杂草的试验。通过观察记载田间杂草的数量和种类变化,初步分析了机插秧条件下杂草发生的规律;通过计算不同处理的防效,分析出各处理的防除效果,总体看来都能达到一定的防控目的,可在生产上推广应用。     

运用气相色谱同时测定稻田稻瘟酰胺和醚菌酯残留量

为了全面准确地了解稻瘟酰胺和醚菌酯在稻田中使用后的生态环境安全性,借助气相色谱分析技术,通过添加回收试验研究并建立了同时测定稻田样品稻瘟酰胺和醚菌酯残留量的方法。结果表明：稻田水样品用二氯甲烷直接萃取;稻田土壤和水稻植株样品用丙酮-水（体积比9∶1）混合液提取,经二氯甲烷萃取后,过弗罗里硅土层析柱净化,再用GC-ECD检测。当稻瘟酰胺和醚菌酯在稻田水、土壤和水稻植株中的添加质量浓度分别为0.05、0.50和1.00 mg/L时,平均回收率为91.0%～106.7%,相对标准偏差为2.3%～12.3%。     

稻田养鸡的研究进展及应用优势

随着现代农业的发展及推进,因农业污染而带来的环境问题越来越突出,为现代农业找寻可持久性发展的方法及向绿色农业的转型成为了当今一大主题.在此大环境下,生态种养不仅实现了物质能量循环利用,还能将生产中的废弃物无害化甚至有用化,在很大程度上解决了现代农业发展带来的污染及资源浪费等问题.从稻田生态种养中的稻—鸡模式出发,介绍其模式优势、经济效益、环境友好性及可操作性,以期对该模式的推广及发展提供参考.     

水稻覆膜旱作对稻田土壤微生物生态质量的影响

在淹水栽培和覆膜栽培方式下,通过田间试验研究了土壤微生物生态质量随水稻生长期的变化情况。研究结果表明,土壤微生物生态质量随着水稻生长期延长而降低,土壤物质周转和循环速度减慢。与淹水栽培方式相比,无论是在水稻分蘖期还是灌浆期,在覆膜栽培方式下土壤微生物生物量相对较高; 土壤电子运输系统活度更强; 土壤蛋白质和土壤总酚含量更高。这说明与淹水栽培方式相比,覆膜栽培方式有利于改善土壤微生物生态质量,加速土壤物质周转和循环。     

稻作区灌溉水流传播的杂草种子与稻田土壤杂草种子库的关系

选择典型稻作区,对灌溉水流传播的杂草种子的种类和数量进行取样调查,并与田埂、灌溉水渠周围生境、下茬麦田的杂草群落及稻田土壤杂草种子库进行比较分析,以研究自然条件下灌溉水流传播的杂草种子与土壤杂草种子库及其他生境杂草群落间的相互关系。 有14科21种杂草种子随灌溉水流输入稻田,这些杂草种子主要隶属禾本科、报春花科、藜科、蓼科等。土壤杂草种子库中共检出19科41种杂草种子,含有所有其他生境中杂草的种子。灌溉水流传播的杂草种子与田埂上、灌溉水渠周围生境、下茬麦田杂草群落及稻田土壤种子库的杂草群落间相似性较高,Sorensen指数均在0.5以上。     

褐飞虱越冬种群和田间种群的致害性比较

比较研究了当年采自田间的褐飞虱种群与上一年虫源在室内越冬繁殖种群对不同抗虫品种的致害性差异。结果表明室内越冬种群和田间种群对水稻苗期的致害性相同,均表现为明显的生物型２特性。高龄若虫对不同抗性品种ＴＮ１、ＩＲ２６和ＡＳＤ７的选择性无显著差异,但均以ＡＳＤ７的最低。室内种群在３个品种上的若虫历期均比田间种群短２～３ｄ,但同一种群在不同品种之间的若虫期存活率和历期的差异不明显。     

稻田养鸭对水稻产量及效益的影响

为掌握稻田养鸭技术,有效提高水稻和养鸭的综合效益,特进行此试验。结果表明,稻田养鸭地由于不用化肥、农药,稻米质量明显提高,有一定增产效果,比对照平均增产10.6%,增加收入2 130元/hm2,具有显著的经济效益和社会效益。由于这项技术不用农药,减少了农药对生态环境的污染,对发展绿色农业以至于有机农业奠定了基础。     

寒地水稻移栽田防治稗草分期施药技术研究

针对常规寒地水稻移栽田前期除稗剂多采用一次性施药,药效和安全性差的问题,通过对寒地水稻移栽田稗草的防治采取插前5～7 d、插后15～20 d分期施药试验研究,结果表明：分期施药对稗草防治效果好,提高了对水稻的安全性。     

寒地水稻移栽田防治稗草分期施药技术研究

针对常规寒地水稻移栽田前期除稗剂多采用一次性施药,药效和安全性差的问题,通过对寒地水稻移栽田稗草的防治采取插前5～7 d、插后15～20 d分期施药试验研究,结果表明:分期施药对稗草防治效果好,提高了对水稻的安全性。     

褐飞虱越冬种群和田间种群的致害性比较

 比较研究了当年采自田间的褐飞虱种群与上一年虫源在室内越冬繁殖种群对不同抗虫品种的致害性差异。结果表明室内越冬种群和田间种群对水稻苗期的致害性相同,均表现为明显的生物型2特性。高龄若虫对不同抗性品种TN1、IR26和ASD7的选择性无显著差异,但均以ASD7的最低。室内种群在3个品种上的若虫历期均比田间种群短2～3 d,但同一种群在不同品种之间的若虫期存活率和历期的差异不明显。     

稻田养鳖对水稻产量形成及稻米品质的影响

为了探究稻田养鳖对水稻产量形成和稻米品质的影响,于2018年在湖南省长沙县明月村采用田间试验,比较黄华占稻鳖共作再生季(RHT)、Y两优800稻鳖共作再生季(RYT)、黄华占常规单作再生季(RHN)、Y两优800常规单作再生季(RYN),4种模式的稻米产量和品质(外观品质、加工品质、蒸煮品质、食用品质).结果显示:稻鳖共作模式有利于增加水稻有效穗数、实粒数,显著提升再生稻的产量;提高出糙率、精米率和整精米率,改善稻米的加工品质;降低垩白率和垩白度,提升稻米的外观品质;但对于稻米RVA特性和蛋白质的含量及组成两个品种的作用效果不同.     

Association of Pythium and Phytophthora with Pre-emergence Seedling Damping-off of Soybean Grown in a FieldConverted from a Paddy Field in Japan

Abstract

In Japan, soybean is usually cultivated in fields that have been converted from rice paddies, and poor seedling establishment due to pre-emergence seedling damping-off is often observed during the rainy season. In this study, the factors that cause the damping-off in flooded soil were investigated under high soil moisture conditions in a greenhouse and in agricultural fields. In sterilized soil sampled from a soybean field, seedlings emerged well under 48-hr flooded conditions. In unsterilized soil, soybean seeds treated with the fungicide, mancozeb+metalaxyl exhibited much higher emergence rates even under 48-hr flooded conditions than the seeds treated with oxytetracycline +streptomycin, benomyl, or flutolanil. Pythium, Phytophthora, Mucorales, Trichoderma, Geotrichum-like microorganisms, and some fungi producing conidia in a false head, were isolated from decayed seedlings. Of the isolated microorganisms, oomycete microorganisms, Pythium helicoides, other Pythium sp., and Phytophthora sp. were pathogenic to soybeans under flooded conditions. As the length of the flooding period increased, pre-emergence seedling rot also increased. However, the pathogenic oomycetes rarely caused pre-emergence seedling rot under conditions without flooding. Furthermore, under flooded conditions, the damage caused by these pathogens was reduced by treating the seeds with mancozeb+metalaxyl. These results indicate that oomycete microorganisms are involved in pre-emergence seedling damping-off under flooded soil conditions.     

Peach orchard protection strategies and aphid communities: Towards an integrated agroecosystem approach

Aphid populations, including a widespread pest, Myzus persicae, are known to be affected by cultural practices, plant growth and natural regulation, but their control in orchards most frequently relies on regular treatments aiming to avoid direct damage and virus transmission. This study aimed first at characterising farmers’ management strategies towards aphids and, secondly evaluating them in terms of efficiency and impact on aphid natural enemies. Protection methods were first identified through semi-open interviews and peach orchard pesticide records from 19 organic and conventional fruit farms in south-eastern France. It appeared that in addition to the regular use of direct control, farmers also used cultural and/or alternative methods and various decision-making indicators to optimise their orchard crop protection. Comprehensive variables based on the technical guidelines of the IOBC (International Organisation for Biological and Integrated Control) for crop protection made it possible to differentiate four strategies: intensive, optimised, input-substitution and integrated. Visual monitoring of aphid infestations and of beneficial populations was performed at the plot level. Brachycaudus schwartzi and Myzus varians were the most frequently encountered aphid species but the structures of the communities were affected by protection strategies: the more integrated the strategy, the more diverse and abundant the aphids. The two most effective strategies were dominated by chemical treatments, whereas the other two, less detrimental to aphid antagonists, were mostly carried out by organic farmers. Variations in aphid communities were related to: (i) the use of toxic products, correlated with low-infestations and low-abundance and diversity of antagonists; (ii) alternative and cultural methods (such as mowed ground cover and manual pruning of infested branches, respectively) that promoted high populations of both guilds. Unexpectedly, the structures of these communities were not related to the number of treatments, management of tree vigour or of the surrounding environment. The four strategies identified can be further interpreted as steps towards a redesign of orchard protection where integrated organic farming would be the most advanced stage. However, the paradox between effective protection strategy and biodiversity conservation still remains, casting doubts on the agroecological concept of sustainability.     

台安县水稻田养分含量现状及改良措施

近些年,台安县农业技术推广中心实施了测土配方施肥工程,对包括14 666 km2水稻在内的耕地土壤开展了土壤养分分析测定工作,基本查清了台安县水稻田土壤养分现状。内文通过把台安县水稻田测土配方施肥工程的测土数据与第二次土壤普查结果相比较,分析了现状,并针对实际情况,提出具体改良措施。     

Rice Production in Unfertilized Paddy Field: Mechanism of grain production as estimated from nitrogen economy

Abstract

Rice grain production in a long- term unfertilized paddy field was compared with that in an adjacent paddy field which had been supplied with the standard level of fertilizers in 1980-1998 to elucidate the mechanism of maintained grain production in the unfertilized field. Average grain yield (brown rice) in the unfertilized paddy field was 382.7 g m^–2 while that in the fertilized field in the adjacent field was 480.0 g m^–2, indicating that 80% of grain production was constantly maintained without supplying any nitrogen fertilizer. The amount of nitrogen absorbed by rice plants for producing 1 g grain was estimated to be 14.1 mg, 55% higher than that in the fertilized field in terms of grain production efficiency. The amount of nitrogen absorbed by rice plants per year in the unfertilized field was calculated to be 5.4 g m^–2. This amount of nitrogen should have been supplied annually to maintain the stable grain production for the period of 18 years. Quantitative analysis of nitrogen in the unfertilized field demonstrated that 1.4 g m^–2 of nitrogen was supplied from irrigation water containing suspended solids, 0.68 g m^–2 from biological fixation, and 9.0 g m^–2 from soil, respectively, to maintain the stable grain production. Total nitrogen of soil in the unfertilized paddy field had been maintained at a constant level during these 18 years, suggesting that grain production of around 380 g m^–2 (brown rice) could be supported without fertilization for an extended period of time.     

稻田干湿交替过程生理生态效应研究综述

稻田干湿交替通过调节水稻生理活性特别是根系活性提高水稻产量,同时对减少温室气体排放,提高水分利用率,改善土壤通气状况,调节田间小气候有重要作用,是实现节水高产的重要技术措施。综述了稻田干湿交替灌溉的生理生态基础及其对水稻植株地上部分和根系生理特性、产量和品质、温室气体排放及土壤碳、氮矿化等的影响,并对稻田干湿交替实施中存在的问题及研究中应当关注的问题进行了探讨,以期为农业的可持续发展提供参考。