共查询到20条相似文献，搜索用时 500 毫秒
1.
K. Senthilkumar P.S. Bindraban T.M. Thiyagarajan N. de Ridder K.E. Giller 《Agricultural Systems》2008
The looming water crisis and water-intensive nature of rice cultivation are driving the search for alternative management methods to increase water productivity in rice cultivation. Experiments were conducted under on-station and on-farm conditions to compare rice production using modified methods of irrigation, planting, weeding and nutrient management with conventional methods of cultivation. Farm surveys were used to evaluate adoption of modified rice cultivation method. On-station experiments showed that, a combination of water-saving irrigation, young seedling or direct seeding, mechanical weeding and green manure application increased the rice water productivity though the largest yields were obtained for a combination of conventional irrigation, young seedling or direct seeding, mechanical weeding and green manure application. On-farm experiments demonstrated a yield advantage of 1.5 t ha−1 for the modified method over conventional method. We found, however, that yield advantages were not the sole factor driving adoption. Associated changes required in management, including the increased labour demand for modified planting, unwillingness of agricultural labourers to change practices, difficulties with modified nursery preparation and the need to replace cheaper women’s labour for hand weeding with more costly men’s labour for mechanical weeding, all reduced the chance of adopting the modified rice cultivation method. Risks associated with water-saving irrigation, such as uncertainty about the timing and amount of water release for irrigation affect adoption adversely as well. There was no incentive for farmers to adopt water-saving irrigation as water from reservoirs and electricity for pumping well-water are both free of charge. To date farmers continue to experiment with the modified cultivation method on a small part of their farms, but are unlikely to adopt the modified method on a large-scale unless policies governing water management are changed. 相似文献
2.
K. Senthilkumar P.S. Bindraban N. de Ridder K.E. Giller 《Agricultural Water Management》2009,96(12):1851-1860
Efficient water use in rice cultivation is a prerequisite for sustaining food security for the rice consuming population of India. Novel rice production practices, including water-saving techniques, modifications in transplanting, spacing, weeding and nutrient management, have been developed and shown to be effective on farm, but adoption of these techniques by farmers has remained restricted. Potential constraints include technical difficulties with new practices, and labour and gender issues which differ between farms. On the basis of a rapid survey of 100 rice-based farms, four farm types were identified based on their socio-economic and biophysical characteristics. Detailed farm surveys were conducted on three representative farms of each farm type to evaluate land use patterns, use of inputs such as water, labour, nutrient, capital and machinery, income from crop and animal production and off-farm activities. Opportunities exist for one or more new rice cultivation techniques to be adopted in all the four farm types. For all farm types, however, the opportunities for use of water-saving irrigation were the least promising. In general, adoption of water-saving irrigation will not improve farmers’ livelihoods despite its importance in reducing water scarcity problems at regional scale. At farm scale, the potential for adoption of water-saving irrigation depends on the season, location of fields and the irrigation source. Changes in government policies such as rules and regulations, pricing, institution building and infrastructure development, as well as training and education of farmers are needed to improve the adoption of modified methods for rice cultivation. 相似文献
3.
不同灌溉方式下水稻产量性状相关性及通径分析 总被引：2，自引：0，他引：2
以杂交水稻二优培九为试验材料,利用测坑栽培,比较了4种灌溉方式下的水稻产量性状,并对其进行了相关性及通径分析,结果表明,与淹水灌溉相比,间歇灌溉、半干旱栽培和干旱栽培比淹水灌溉下水稻产量分别增产16.20%、减产12.90%和减产37.87%;单株有效穗数、每穗实粒数、结实率和千粒重与单株理论产量之间呈极显著正相关,相关系数分别为0.73892、0.57864、0.58591和0.62008,而单株有效穗数与每穗颖花数、每穗实粒数和一次枝梗数呈较弱的负相关。试验结果表明,间歇灌溉为南方稻区较适宜的灌溉方式。在制定水稻高产栽培措施时,应加强稻田水分管理,在提高千粒重的同时,主攻并协调好单株有效穗数和每穗实粒数。 相似文献
4.
Opportunities for water saving with higher yield from the system of rice intensification 总被引：1，自引：0，他引：1
The system of rice intensification (SRI) developed in Madagascar, is showing that by changing the management of rice plants,
soil, water and nutrients it can increase the yields of irrigated rice by 25–50% or more while reducing water requirements
by an equivalent percent. This gives farmers incentive to reduce their irrigation water use when growing rice, especially
since SRI methods can also reduce farmers’ costs of production which increases their net income ha−1 by even more than yield. Even though these results sound fantastic, the validity of SRI concepts and practices has been demonstrated
in more than 20 countries to date. This article considers, first, the methods that make these improvements possible and how
these are achieved. It then briefly surveys SRI experience in five Asian countries, incentives in addition to yield, water-saving
and profitability for adopting SRI, and possible limitations or disadvantages with the methodology. Next, it comments on the
debate over SRI in the agronomic literature and then adds to the empirical record by reporting in some detail on SRI evaluations
in two of India’s main rice-growing states, Andhra Pradesh and Tamil Nadu, where water availability is becoming more problematic
and where SRI use is spreading. Finally, the article briefly discusses some implications of saving irrigation water by changing
resource management rather than by using on more or different inputs.
相似文献
| Norman UphoffEmail: |
5.
稻田农业节水栽培配套技术的研究 总被引：6，自引：3，他引：6
在湖南攸县、双峰进行的田间试验结果表明 ,稻草覆盖免耕结合浅湿灌溉的稻田农业节水栽培配套技术与传统的栽培方法比较 ,能提早和促进水稻分蘖 ,提高水稻根系活力、功能叶叶绿素含量和干物质的积累 ,降低水稻纹枯病的发生 ,晚稻产量达 8790 kg/ hm2 ,增产率达 10 .2 %;同时 ,能提高灌溉水的生产效率 ,节约灌溉用水量 ,晚稻田灌水次数减少 40 %,每公顷节约灌水量 112 3.5 m3、节省水稻生产成本 5 10元、纯收入增加 1437元。 相似文献
6.
《Agricultural Systems》2005,85(2):183-201
Seasonally-specific cultivation patterns of farm crop enterprises often create periodic labor shortages. New technologies that require labor inputs during such labor-scarce seasons are less likely to be adopted. Financial ex ante assessments of technology alternatives, however, neglect the implications of seasonal labor shortages. Standard returns to labor estimates assume that the value of labor to farmers is constant despite temporary increases in demand. This paper develops an alternative measure, returns to opportunity-costed labor (RTOCL), which discerns the seasonally-changing costs of labor. RTOCL more accurately reflects farmer decision criteria and serves as a useful measure in ex ante analysis of technology interventions. A case study of a bush fallow agricultural system in the Peruvian Amazon illustrates how seasonal labor shortages lead to farm management tradeoffs that affect the prospects of technology adoption. Two improvements of a new upland rice variety are contrasted: higher yield versus early maturity. Empirical results of an agro-economic mathematical model reveal that the early maturity characteristic enables rice to become more complementary to peak-season labor demands of the agricultural system. This early maturity characteristic permits farmers to cultivate larger areas and reap greater financial benefits than a variety with a high yield characteristic. Model results support the need to address heterogeneous seasonal labor demands when developing and disseminating agricultural technologies intended to benefit resource-poor farmers. 相似文献
7.
8.
Yasuhiro Tsujimoto Takeshi Horie Hamon Randriamihary Tatsuhiko Shiraiwa Koki Homma 《Agricultural Systems》2009,100(1-3):61-71
The system of rice intensification (SRI) developed in Madagascar in the 1980s has been promoted as an integrated crop and resource management approach to rice-cultivation, especially for resource-limited smallholder farms. While advocates have claimed that SRI could boost rice yields with less external input, many criticisms have challenged its effectiveness regarding yields and applicability to larger-scale rice farming systems. In this study, we conducted a field survey and on-farm experiments to assess rice yield performance and key management practices on a few of the early SRI-practicing smallholder farms in the central highland of Madagascar.Rice grain yields at the survey fields were 9.9 t ha−1 maximum without using mineral fertilizer. Deep plowing to the depth of 25–30 cm as well as SRI practices have been conducted continuously since the early 1990s. In addition, an effective drainage system facilitated intensive water management at these high-yielding fields. On-farm experiments demonstrated some yield increases with no interaction for the examined SRI practices, though the effects were not great enough to explain the high yields at these fields. The soils of these high-yielding fields contained relatively large amounts of soil organic carbon (SOC) from the surface to the deep soil layers, and the soil mineralizable nitrogen was closely correlated with rice grain yields.The results indicated that the high yields at the fields of those who were early to adopt SRI were mainly due to the soil fertility associated with great nitrogen-supplying ability, rather than ‘synergetic effects’ of the SRI components. This high N-supplying ability of the soil and accumulated SOC from surface to deep soil layers were attributable to the long-term combined practices of extensive organic applications and deep plowing. Soil hydrology could be another key factor stimulating high rates of soil N-mineralization.These management practices were, however, only applied to the limited numbers of fields within less than 1.0 ha of total landholdings of these farmers due to the great demand in labor and organic resources and the difficulty in controlling irrigation water. Intensive weeding and widely spaced transplanting of young seedlings were also performed in the fields with irrigation and drainage systems sufficient to avoid yield losses from flooding and drought. Although extensive and long-term systematic research is further required to fully assess the benefits of this sort of intensive management as opposed to conventional methods, the preferential allocation of intensive management by the successful SRI-adopters might be the implication of its location-specificity and difficulty in scaling up even within the resource-limited smallholder farms. 相似文献
9.
水稻覆膜灌溉对生态环境的影响研究 总被引：3，自引：1，他引：2
通过大田试验,与浅湿灌溉(CK1)和浅水灌溉(CK2)相比较研究了覆膜灌溉对水稻生态环境的影响。结果表明,覆膜灌溉条件下稻田空气相对湿度低于CK1和CK2,气温和地温高于CK1和CK2,其中地温的增温幅度在返青期最大,随着水稻叶面积的增加逐渐减少,在所观测的深度范围内(15cm)随着土层深度的增加而增大。覆膜灌溉较CK1、CK2生育进程加快,生育期提前和缩短。抽穗开花期水稻的抵抗力差,若遇低温高湿情况易感染稻瘟病,由于覆膜区水稻抽穗早避免了低温天气,加上覆膜还可以提高空气温度、降低空气湿度,使覆膜区水稻的受病害程度明显降低。覆膜水稻的生长量大(分蘖数、每穗总粒数和千粒重高),其无效分蘖数也较高,因此,建议覆膜水稻要适当稀植以增加成穗率,同时降低成本。覆膜水稻产量较CK1高2.6%,较CK2高5.7%;经济效益较CK1高1.1%,较CK2高6.2%;灌溉水生产率为1.56kg/m3,比CK1高38%,比CK2高95%。 相似文献
10.
节水高产的浅湿灌溉技术较适合南太湖地区的水稻生产。试验选用苏南太湖地区水稻土中有代表性的粘土和重壤土作试验载体 ,系统地探讨了浅湿灌溉对水稻生理、生态及稻田生态环境的影响 ,水稻平均比浅水勤灌增产 6.1 %。经对降水利用率、稻田耗水量、灌水量测定 ,浅湿灌溉比浅水勤灌分别增加 1 4 .6%和减少 1 9.2 %和 30 % ,收到了节水高产的效果。对地下水埋深和土壤含水率对应关系的测定 ,得出 ,稻田落干时地下水埋深以 30 cm为宜 (烤田期除外 )。在此范围内 ,地下水埋深每下降 1 0 cm,土壤含水率下降 1 %～ 5%。据此大田试验 ,得出了水稻的最优灌溉模式 相似文献
11.
12.
郭淑鲜 《农业机械化与电气化》2009,(1):15-17
在开原地区进行水稻测土配方施肥技术应用示范，结果表明：测土配方施肥比常规施肥平均增产稻谷45．1kg／667m2，增产率达7．58％：节省肥料施用量3．15kg／667m2增加经济效益84．76元／667m2。这说明推广应用测土配方施肥技术切实可行，增产、节肥效果稳定。 相似文献
13.
旱作水稻水肥耦合模型及经济效应 总被引：1，自引：0，他引：1
为了探讨膜下滴灌旱作水稻水分、肥料与产量之间的关系,采用通用旋转组合设计试验方法,进行膜下滴灌旱作水稻水肥耦合模型试验,并对其应用前景进行了比较分析.在供试土壤膜下滴灌条件下,灌溉定额、氮、磷与水稻产量之间符合三元二次回归模型,其一次项、二次项及水氮交互项回归系数均达显著水平,三因素的增产作用从大到小依次为灌溉定额、施氮量、施磷量.采用此模型计算的预测产量与实际产量之间呈高度正相关,预测准确度达99%.由此计算得出最高产量灌溉定额及其施肥量、经济最佳灌溉定额及其施肥量.提出实现目标产量的水肥最优组合方案:若以9 300~9 600 kg/hm2为目标产量,则灌溉定额、氮、磷用量分别为9 730~10 500 m3/hm2,272~363 kg/hm2,136~147 kg/hm2;若同时考虑经济效益,则最佳的灌溉定额、氮、磷肥用量分别为8 500~9 015 m3/hm2,225~240 kg/hm2,90~120 kg/hm2.对比不同种植模式表明,膜下滴灌旱作水稻的产量与播后上水直播基本持平,其成本与育秧移栽种植持平,但水分生产效率(1.06 kg/m3)远远高于其他3种种植方式.与传统育秧移栽种植相比较,膜下滴灌旱作水稻节水50%,节约肥料30%以上. 相似文献
14.
K. Senthilkumar M.T.M.H. LubbersN. de Ridder P.S. BindrabanT.M. Thiyagarajan K.E. Giller 《Agricultural Systems》2011,104(1):82-93
Improving water use and nitrogen efficiencies is of overall importance to society at large - to conserve scarce water resources and prevent environmental pollution. Efficient cultivation practices for rice which had no yield penalty were not adopted by farmers because of the open access to water free of charge. Well-chosen combinations of policy measures are thus needed to stimulate adoption of new cultivation practices. We developed a multi-objective linear programming (MGLP) model to explore the impact of: (i) modified rice cultivation including water-saving irrigation on farm profit; (ii) water pricing and water quota government policies on adoption of modified rice cultivation by farmers; (iii) a combination of (i) and (ii) to achieve the objectives of both farmers and society at large, and (iv) to study the trade-offs between income, water and nitrogen use. The analysis was carried out on four rice-based farm types for the state of Tamil Nadu, South India. Model results showed that observed farm profit of all four farm types could be increased using current practices simply by optimizing land use for specific crops. Adoption of modified rice cultivation further increased farm profit. Water-saving practices were selected only when water pricing was introduced. Farm profits were reduced even at low water prices but were compensated by farmers through adoption of modified rice cultivation. The combination of policies that stimulate adoption of modified rice cultivation was effective in achieving both increased farm income and water savings. The required water prices differed across farm types and seasons and impacted poor resource-endowed farmers the most. Providing water quotas could protect the poor resource-endowed farmers. The model helped to identify the optimal water price and water quota for each farm type to achieve both the objectives of farmers and society at large. Opportunities for reducing water use and avoiding environmental pollution at acceptable profits are available for all farm types, but need to be tailored to the farmers’ resource endowments. 相似文献
15.
Rajeeb K. Mohanty S.K. Jena A.K. Thakur D.U. Patil 《Agricultural Water Management》2009,96(12):1844-1850
We examine the productivity of deepwater rice-fish systems and management strategies that include high-density initial stocking and selective harvesting. All species of fish and prawns grow faster after 120 days of rearing, probably due to periodic selective harvesting that minimizes the competition for food and space, as well as physiological stress at reduced density. We observe a higher survival rate, a lower apparent feed conversion ratio (1.77) and higher fish yield (14.1%) in rice-fish culture with selective harvesting (T1) than in rice-fish culture without selective harvesting (T2). The highest paddy yield was recorded in T1, primarily due to the higher number of panicles per m2 (139.5) and the number of filled grains per panicle (111.5). The increase in paddy yield over rice mono-cropping was higher in T1 (25%) than T2 (16.9%). The smaller number of panicles (122.2/m2) and filled grains (98.5 per panicle) in rice mono-cropping was probably due to the absence of fish and prawns in the field as fish and prawns improve soil fertility, recover lost energy, and adjust energy flow by consuming plankton, weeds, insects and bacteria that compete with rice for nutrients. The highest rice equivalent yield (38.5 t ha−1), the output value-cultivation cost ratio (1.56) and net water productivity (Rs. 7.30/m3) in deepwater rice-fish culture was recorded when selective harvesting was practiced. This eco-friendly dual production system (rice and fish) and on-dyke horticulture, which generate near-term lucrative returns and generates employment opportunities, can be adopted and expanded in lowlands and waterlogged areas. 相似文献
16.
【目的】探索水稻蓄雨间歇灌溉模式节水减排效益。【方法】以鄱阳湖区双季早晚稻为试验材料,采用大田和测坑试验,研究了水稻蓄雨间歇灌溉模式对灌溉定额、排水定额、降雨有效利用率、产量、稻田水分生产率,以及氮、磷排放量的影响,并与间歇灌溉和常规淹水灌溉试验进行了分析比较。【结果】与淹水灌溉、间歇灌溉相比,蓄雨间歇灌溉灌排水量、灌排次数明显减少。双季早晚稻年平均灌水量分别减少975m^3/hm^2和1251m^3/hm^2,年平均灌水次数分别减少8次和7.5次;年平均排水量分别减少729 m^3/hm^2和893 m^3/hm^2,年平均排水次数分别减少5.8次和3.1次;蓄雨间歇灌溉降雨有效利用率明显提高。早稻降雨利用率分别提高12.40%和9.14%,晚稻分别提高6.84%和6.42%;蓄雨间歇灌溉模式下,双季早晚稻总氮排放量年平均减排7.64 kg/hm^2和3.12 kg/hm^2,减排幅度34.93%和14.26%;双季早晚稻总磷排放量0.180kg/hm^2和0.095kg/hm^2,减排幅度37.25%和70.59%。【结论】蓄雨间歇灌溉模式具有明显的节水、减排和提高降雨有效利用率的效果,在我国南方多雨地区具有较强的推广应用空间。 相似文献
17.
Crop consumptive water use and productivity are key elements to understand basin water management performance. This article presents a simplified approach to map rice (Oryza sativa L.) water consumption, yield, and water productivity (WP) in the Indo-Gangetic Basin (IGB) by combining remotely sensed imagery, national census and meteorological data. The statistical rice cropped area and production data were synthesized to calculate district-level land productivity, which is then further extrapolated to pixel-level values using MODIS NDVI product based on a crop dominance map. The water consumption by actual evapotranspiration is estimated with Simplified Surface Energy Balance (SSEB) model taking meteorological data and MODIS land surface temperature products as inputs. WP maps are then generated by dividing the rice productivity map with the seasonal actual evapotranspiration (ET) map. The average rice yields for Pakistan, India, Nepal and Bangladesh in the basin are 2.60, 2.53, 3.54 and 2.75 tons/ha, respectively. The average rice ET is 416 mm, accounting for only 68.2% of potential ET. The average WP of rice is 0.74 kg/m3. The WP generally varies with the trends of yield variation. A comparative analysis of ET, yield, rainfall and WP maps indicates greater scope for improvement of the downstream areas of the Ganges basin. The method proposed is simple, with satisfactory accuracy, and can be easily applied elsewhere. 相似文献
18.
不同灌溉方式对水稻需水量和生长的影响 总被引：4，自引：0，他引：4
利用桶栽试验,研究了在不同灌溉方式及不同蒸发渗漏处理下的水稻需水量和对水稻生长的影响。结果表明:水稻以拔节孕穗期需水强度最高,无水层、干干湿湿和70%水分处理需水量分别比有水层处理减少42.5%、51.3%和57.6%;水稻叶面蒸腾量、棵间蒸发量与田间渗漏量占总耗水量的百分比分别为60.1%、16.4%和23.5%;干干湿湿处理水分利用率达到1.6 kg/m3,叶片光合速率最大,收获指数最高,从节水和增效的角度看,以干干湿湿灌溉最佳。 相似文献
19.
《Agricultural Systems》2007,92(1-3):318-333
This paper presents an econometric analysis of the influence of soil fertility status on productivity and resource use in rice production utilizing survey data from 21 villages in three agro-ecological regions of Bangladesh. Detailed crop husbandry input–output data were collected from 380 paddy rice (Oryza sativa) farmers. Data collected included fertilizer, pesticide, labour, animal power services, irrigation, farm capital assets and rice yield. The soil fertility status in each region was determined by analysis of soil organic carbon, available nitrogen, phosphorus and potassium concentration. Analysis was based on a profit function, where the selected soil fertility parameters were incorporated as yield controlling variables. Results revealed that soil fertility has a significant influence on both productivity and farmers’ resource allocation decisions. Output supply was significantly higher in fertile regions and input use was significantly lower. This observation indicates that in policy terms technological initiatives should be targeted at measures to identify areas of lower soil fertility so that inherent soil-based productivity restrictions can be minimized. In part this will be facilitated by the transfer of indigenous knowledge from farmers in higher productivity areas, thus increasing rice production and raising the competitiveness of Bangladeshi rice farmers. 相似文献