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1.
Field experiments were conducted in Bhubaneswar, Orissa, India, during the dry season (January–May) in 2008 and 2009 to investigate whether practices of the System of Rice Intensification (SRI), including alternate wetting and drying (AWD) during the vegetative stage of plant growth, could improve rice plants’ morphology and physiology and what would be their impact on resulting crop performance, compared with currently recommended scientific management practices (SMP), including continuous flooding (CF) of paddies. With SRI practices, grain yield was increased by 48% in these trials at the same time, there was an average water saving of 22% compared with inundated SMP rice. Water productivity with AWD-SRI management practices was almost doubled (0.68 g l−1) compared to CF-SMP (0.36 g l−1). Significant improvements were observed in the morphology of SRI plants in terms of root growth, plant/culm height, tiller number per hill, tiller perimeter, leaf size and number, leaf area index (LAI), specific leaf weight (SLW), and open canopy structure. These phenotypic improvements of the AWD-SRI crop were accompanied by physiological changes: greater xylem exudation rate, crop growth rate, mean leaf elongation rate (LER), and higher light interception by the canopy compared to rice plants grown under CF-SMP. SRI plants showed delayed leaf senescence and greater light utilization, and they maintained higher photosynthetic rates during reproductive and grain-filling stages. This was responsible for improvement in yield-contributing characteristics and higher grain yield than from flooded rice with SMP. We conclude that SRI practices with AWD improve rice plants’ morphology, and this benefits physiological processes that result in higher grain yield and water productivity.  相似文献   

2.
Experiments were conducted at irrigated and rainfed lowland rice sites in Bangladesh to assess the performance of management practices that have become known as the System of Rice Intensification (SRI). At a research station, SRI management principles such as seedling age, plant spacing, application of organic manure, seedling densities, duration of planting, planting shape and time of planting were evaluated under SRI management as compared to previously established Best Management Practices (BMPs). In on-farm trials, SRI was compared with BMP on 40 farmers’ fields. Nutrient inputs and water management in BMP and SRI treatments were kept at comparable levels. Seedling age, ranging from just sprouted seed to 40-day-old seedlings, had no effect on grain yield in the winter season. In a plant spacing experiment subject to SRI, the highest and lowest grain yields of 7.82 and 5.41 t ha−1 were obtained with spacing of 25 cm × 15 cm (narrow) and 40 cm × 40 cm (wide), respectively. In SRI, seedling density (1–2 seedlings per hill), planting durations (≤15 min to 1–3 h after uprooting) or root placement (L-shape and J-shape) had no effect on grain yield. With regard to time of planting, the highest grain yields were observed with transplanting in the 3rd week of December, with no difference between SRI and BMP management systems. In on-farm trials, BMP gave significantly higher grain yield compared to SRI and farmers’ practice in a triple-cropped area, but grain yields were similar with SRI in a double and single-cropped area when spacing was narrow. The highest profit was obtained with BMP followed by SRI and farmers’ practice in the single-cropping area. Major findings from this study are that under comparable levels of net nutrient input and water management (i) well-implemented BMPs for rice are more efficient for producing high yields than SRI and (ii) there is no intrinsic yield advantage of SRI that could be caused by its individual crop management techniques or some unknown synergism of the different SRI practices proposed.  相似文献   

3.
Cereal production is chronically deficit in the Timbuktu region of Mali, sufficient for only 4.5 months of annual household consumption. Small-scale, village-based irrigation schemes, usually 30–35 ha in size, irrigated by a diesel motor pump, have become important to improve food security in this arid region. The NGO Africare has worked during the past 12 years with farmers in Goundam and Dire circles to establish irrigation schemes and provide them with technical assistance. In 2007, Africare undertook a first test of the System of Rice Intensification (SRI) in Goundam circle. After farmers observed a yield of 9 t ha−1 of paddy compared to 6.7 t ha−1 in the control plot there was interest in larger scale testing of the SRI system. In 2008, Africare, in collaboration with the local Government Agriculture Service and with support from the Better U Foundation, implemented a community-based evaluation of SRI with 60 farmers in 12 villages. Farmers in each village selected five volunteers, who each installed both SRI and control plots, side by side, starting the nurseries on the same day and using the same seed. For SRI plots, seedlings were transplanted one plant hill−1 at the two-leaf stage (on average, 11.6 days old), with spacing of 25 cm × 25 cm between hills and aligned in both directions. This allowed farmers to cross-weed with a cono-weeder, on average 2.4 times during the season. In the control plots, farmers planted 3 plants hill−1 with seedlings 29.4 days old and spaced on average 23.7 cm, not planted in lines. Weeding was done by hand. 13 t ha−1 of organic matter was applied under SRI management, and 3 t ha−1 in the control plots. Fertilizer use was reduced by 30% with SRI compared to the control. Although alternate wetting and drying irrigation is recommended for SRI, this was not optimally implemented due to constraints on irrigation management within the scheme; thus water savings were only 10% compared to the control. Average SRI yield for all farmers reached 9.1 t ha−1, with the lowest being 5.4 t ha−1 and highest being 12.4 t ha−1. SRI yields were on average 66% higher than the control plots at 5.5 t ha−1, and 87% higher than the yields in surrounding rice fields at 4.9 t ha−1. Number of tillers and panicles hill−1, number of tillers and panicles m−2, and panicle length and number of grains panicle−1 were clearly superior with SRI compared to control plants. Farmers tested five varieties, all of which produced better under SRI. The SRI system allowed for a seed reduction of 85–90%: from 40–60 kg ha−1 for the control plots to 6.1 kg ha−1 under SRI. Although production costs per hectare were 15% higher for SRI, revenue was 2.1 times higher than under the control. Farmers were very satisfied with these results. In 2009/2010, Africare and the Government’s agriculture service worked with over 270 farmers in 28 villages to scale up SRI practices and to test innovations, including composting techniques, optimization of irrigation, and techniques to reduce labor requirements and production costs. The good crop performance along with other advantages was confirmed in this third year with SRI yields of 7.7 t ha−1 (n = 130 farmers) compared to 4.5 t ha−1 in farmers’ fields.  相似文献   

4.
A field experiment was conducted to investigate the effects of intermittent versus continuous irrigation, together with different degrees of organic fertilization, on the growth and yield of hybrid rice, looking also at the functioning of the rhizosphere as this is a key element affecting crop performance. The crop management practices employed generally followed the recommendations of the System of Rice Intensification (SRI). The aim of the research was to learn how water management and organic fertilization together would affect crop outcomes. Under intermittent water application as recommended with SRI management (aerobic irrigation, AI), grain yield increased by 10.5–11.3%, compared to standard irrigation practice (continuous flooding, CF). The factor that contributed most to higher yield was increased number of grains per panicle. It was seen that under the range of organic fertilization treatments evaluated, intermittent irrigation compared with CF promoted greater dry matter production and higher leaf area index (LAI) during the main growth stages. Also, the combination of intermittent irrigation and organic material applications significantly increased soil redox potential (Eh), compared with CF, and also the numbers of actinomycetes in the rhizosphere soil. Actinomycetes were evaluated in this study as an indicator of aerobic soil biota. It was seen that with intermittent irrigation, the application of organic material improved the functioning of the rhizosphere and increased yield. However, these results based on 2 years of study reflect relatively short-term effects. The effects of longer-term water management and soil fertilization regimes should be also examined, to know whether these effects continue and, if they do, whether they become greater or less.  相似文献   

5.
Promising results from an increasing number of field evaluations of the System of Rice Intensification (SRI) conducted in Asia and Africa indicate that African farmers could increase their rice production while lowering costs of operation and reducing the need for water by utilizing its principles and practices. This system relies not on external inputs to raise productivity but on alternative methods for managing rice plants and the soil and water resources devoted to their cultivation. Farmers in sub-Saharan Africa increasingly have to cope with the impacts of adverse climate effects because water shortages and long dry spells during the cropping season are becoming common, even in lowland rice agroecosystems. SRI management practices create both larger rice root systems that make their plants more resistant to biotic and abiotic stresses and more conducive environments for beneficial soil microflora and fauna to flourish. Better plant growth and development result from promoting plant–soil synergies. Controlled fertilizer management experiments conducted with SRI practices in The Gambia have showed that grain production can be significantly increased without higher application of inorganic fertilizer and with less requirement for water. SRI management practices with fertilizer application at the national recommended dose produced a grain yield of 7.6 t ha−1. Water productivity was greatly increased, with 0.76 g of grain produced per kg total water input, compared to 0.10 g of grain per kg of water when the crop was continuously flooded. Recent hikes in fuel prices and consequent rises in input costs are making domestic rice production less attractive and importation even more attractive. Computation of production costs showed that SRI production, not needing heavy applications of fertilizer, is economically cost-effective. Achieving yield increases through ever-higher fertilizer applications is not economically or environmentally viable. SRI management with recommended fertilizer applications produced a net return of $853 ha−1 compared to $853 ha−1 compared to 37 when using farmers’ present low-productivity practices.  相似文献   

6.
A 2-year field experiment was conducted during the wet seasons (July–October) of 2008 and 2009 on a Typic Hapludoll Mollisol in Indo-Gangetic Plains Region (IGPR) to: (i) investigate the effects of field water re-ponding intervals and plant spacing on the growth, yield, and water productivity (WP) of two rice cultivars under system of rice intensification (SRI) management, and (ii) assess comparative performance of SRI versus ‘best management practices’(BMP) of rice cultivation. This experiment was designed with 14 treatments, 12 under SRI, and 2 BMP (controls). SRI treatments comprised of 3 irrigation regimes viz, irrigation at 1, 3, and 5 day(s) after disappearance of ponded water (DADPW), 2 plant spacings (20 × 20, 25 × 25 cm), and 2 rice cultivars (Pant Dhan 4 and Hybrid 6444). Two BMP (control) treatments comprised of standard cultivation recommendations for flooding and spacing. The experiment was laid-out in a factorial randomized complete block design with three replications. Statistical analysis of data revealed significant variations in root–shoot characteristics and rice yield under SRI between years, reflecting different rainfall patterns. During 2009, a low rainfall year, the panicle numbers m?2, dry root weight m?2, root volume m?2, filled spikelet number panicle?1, and filled spikelet weight panicle?1 were significantly higher, which resulted in a rice grain yield enhancement by 5.1 % over 2008, when there was unusually heavy rainfall. Climate × irrigation regime interaction revealed a non-significant influence of irrigation regimes on growth and yield during 2008, whereas in 2009, irrigation at 1 DADPW and 3 DADPW increased grain yield by 12.8 and 8 %, respectively over 5 DADPW. Better root–zone soil moisture regimes, balancing water, and oxygen availability were responsible for higher yields under irrigation at 1 and 3 DADPW. In 2008, soil moisture content (SMC) in 0–15 cm layer was 91, 86, and 82 % of field capacity (FC) at panicle initiation, and 88, 80, and 77 % at panicle emergence stage when irrigation was at 1, 3, and 5 DADPW, respectively; the lower layers (15–30, 30–45 cm) retained their SMC between 87 and 94 % of FC at both stages. During 2009, SMC in all the three layers at both stages was more than 85 % of FC when irrigating at 1 DADPW, and a little more than 70 % for the 0–15 cm layer and >80 % for the other two layers when irrigation was done at 3 DADPW. SMC dropped to below 60 % of FC in the 0–15 cm layer and remained between 67 and 77 % of FC in the other two layers, with lower yield resulting when irrigations were applied at 5 DADPW. However, WP was the highest with irrigation at 5 DADPW (38.5 kg ha cm?1). Wider plant spacing (25 × 25 cm) resulted in generally and significantly higher grain yield and WP. On an average, SRI (6.1 t ha?1) resulted in yield advantage of 0.9 t ha?1 over BMP (5.2 t ha?1). Overall, it is inferred that in SRI, wider planting (25 × 25 cm) with field re-ponding at 3 DADPW if there is adequate water availability and at 5 DADPW under limited water supply conditions, may lead to higher rice yields and WP in sub-humid tarai Mollisols of IGPR and comparable agro-climatic conditions in Indian sub-continent.  相似文献   

7.
A demonstration study on Information Technology (IT) field monitoring was conducted in a rice field under the System of Rice Intensification (SRI) environment in Shinshiro City, Aichi Prefecture, Japan. The IT system used in this study consisted of an intelligent sensor node web-server that is equipped with in situ camera and sensor networks for agrometeorological, soil, and plant growth monitoring. Dynamic changes in soil moisture, water level, agrometeorological, and environmental conditions were measured and monitored. With this precision farming set-up, understanding and easy assessment of the salient field conditions and phenomena such as cyclic soil wetting and drying as well as critical crop growth stages were made possible. Based on the findings of the demonstration experiment, the system was effective, reliable, and efficient in monitoring soil moisture parameters and agrometeorological information in remote rice field environment. The actual field conditions were captured well by a combination of images, numerical, and graphical data sets. With this precise information, the frequency of irrigation was found to be every 7 days. The rice field was irrigated up to a moisture level of 0.592 m3/m3 (~600 mV) and allowed to be depleted to a moisture level of 0.417 m3/m3 (~400 mV). With this alternate drying and wetting method (AWD), a 25.71% of irrigation water was saved. In this study, rice production was made more scientific and more reliable. Hence, the use of IT field monitoring system represented a viable medium for the realization of better rice productivity which leads to the ethic of sustainable agriculture.  相似文献   

8.
SRI practices can usually increase the yield of paddy without using special varieties of rice or chemicals. High yield of paddy can be simply achieved through the combination of transplanting single seedlings about 8–10 days old with just two leaves on 40 cm × 40 cm spacing, providing organic fertilizer, and intermittent irrigation. No pesticides are applied. Historically, integrated management of water and crop (particularly rice) in the Philippines, had its beginning with the Spaniards, but more formal events were recorded in the 1950s by Margate (1954) in “Rice: 100 Cavans (50 kg/cavan) per Hectare.” This was followed by the Water Management Manual released in the 1970s by the Asian Development Bank (ADB) and National Irrigation Administration (NIA). Recently, the Southern Philippines Irrigation Sector Project (SPISP), a joint ADB–NIA effort, has commenced trials with the system of rice intensification (SRI) practice. One of the most specific features of SRI is the intermittent irrigation system which requires assured water supply at necessary timing. It is easier to attain assured water supply on timely manner through irrigation management transfer (IMT) which encourages the empowerment of fair water distribution. This article analyzes the merit of IMT for SRI.  相似文献   

9.
A field study was conducted at Al-Mishkhab Rice Research Station (MRRS) during the summer season 2009 to evaluate irrigation water use efficiency (IWUE) using Anbar 33 variety with the System of Rice Intensification compared to traditional methods. During the growth phase, the number of leaves, stems, and roots, and the average plant height were measured every 15 days for the two sets of methods. At maturity, the depth and length of plant roots was assessed, along with leaf area index (LAI) of the flag leaf and plant height. The amount of irrigation water applied was measured by water meter for both methods. SRI principles for plant age, spacing, etc., were implemented in the SRI plots. The results indicated more vigorous growth of roots under SRI methods, reaching 13,004 cm plant−1 compared with non-SRI results of 4,722 cm plant−1. There was 42% increase in grain yield when SRI methods were used. These had water use efficiency (WUE) of 0.291 kg m−2 compared with WUE of 0.108 kg m−2 for non-SRI cultivation, almost a threefold difference. SRI practices reduced the need for irrigation water by 38.5%.  相似文献   

10.
We investigated the use of irrigation water for a successive planting of watermelon followed by Japanese radish in a sand dune area in the Hokuriku Region. The main results were as follows: (1) Upland field tested in the study used a large volume of irrigation water in spite of its location in the Hokuriku Region where rainfall was plentiful. Notwithstanding this, frequent irrigation was considered necessary. (2) Watermelon was cultivated as a Spring–Summer crop with a mean cultivation period of 102 days, during which it was irrigated for 59 days at 1.7-day average intervals with an irrigation volume of 7.1 mm/watering and a total irrigation volume of 428 mm over its entire growing season. The amount of rainfall during the period was 604 mm during 42 days of rainfall. Soil moisture levels in the upland field were kept at relatively high values ranging between pF1.3 and pF1.5 at 15-cm depth with frequent irrigation during no-rainfall period. (3) Japanese radish was cultivated as a Summer–Autumn crop with a mean cultivation period of 71 days during which it was irrigated for 39 days at 1.9-day average intervals with an irrigation volume of 9.4 mm/watering and a total irrigation volume of 358 mm over its entire growing season. The amount of rainfall during the period was 376 mm during 29 days of rainfall. Frequent irrigations were used to maintain the soil moisture levels in the upland field within the range of pF1.4–pF1.6 at 15 cm depth. (4) During the irrigation period, the amount of water used for irrigation was 5.9 mm/day in watermelon and 6.1 mm/day in Japanese radish which are greater than evapotranspiration (ET). In addition, during pre-irrigation, the preparation of the seeding bed can be carried out at the right time which contributes to producing high-quality Japanese radish in adequate quantity. In addition, pre-irrigation for preparation of bed for watermelon transplanting is very important for better time management and high-quality production. For this purpose, the irrigation facilities need to be functioning very well.  相似文献   

11.
To optimize the use of limited water resources, surface irrigation systems in parts of China have introduced a new water saving irrigation method for rice termed alternate wetting and drying (AWD). The basic feature of this method is to irrigate so that the soil alternates between periods of standing water and damp or dry soil conditions from 30 days after crop establishment up to harvesting. However, many Chinese rice farmers still practice the continuous irrigation method with late- season drying of the soil.A comparative assessment of these two methods of on-farm water management for rice was conducted at two sites within the Zhanghe Irrigation System (ZIS) in Hubei province of China for the 1999 and 2000 rice crops. The objective was to evaluate the impact of AWD on crop management practices and the profitability of rice production. In conjunction with irrigation district officials, two sites within ZIS were selected for study, one where AWD was supposed to be widely practiced (Tuanlin, TL) and one where it had not been introduced (Lengshui, LS). It was found that farmers at both sites do not practice a pure form of either AWD or continuous flooding. However, farmers in TL did tend to let the soil dry more frequently than their counterparts in LS.Because most farmers practice neither pure AWD nor pure continuous flooding, an AWD score was developed that measures the frequency with which farmers allow their soil to dry. This AWD score was not significantly correlated with yield after controlling for site and year effects and input use. AWD scores were also not correlated with input use. We conclude that AWD saves water at the farm level without adversely affecting yields or farm profitability.  相似文献   

12.
Waterlogging and salinity problems in major rice growing areas demand policies aimed at better management of land and water resources. This process can be facilitated through regional scale spatially distributed hydrologic–economic models that capture and integrate point scale processes at paddock, farm and irrigation area levels. The study develops an integrated hydrologic–economic framework that integrates hydrologic and economic responses for social and common pool optimum management in the Coleambally Irrigation Area, Australia. The results of hydrological-economic model indicate that the economic units with heavier soils and shallow watertables with minimum groundwater out flows are the best economic locations for growing rice as the total crop water requirements are minimised. Social and common pool optimum scenarios indicates, after accounting for externalities and groundwater dynamics, the optimal net returns could be achieved in about 15 years. There was not much difference between social and common pool optimum, however, common pool optimum show decline in net revenue after 23 years because of shallow watertable rise within 2 m of the surface. The current rice growing policies are mainly based on the clay content of soils and rice water use limits. This work has highlighted the importance of incorporating groundwater dynamics in deciding environmental policies for growing rice.  相似文献   

13.
The presence of arsenic in irrigation water and in paddy field soil were investigated to assess the accumulation of arsenic and its distribution in the various parts (root, straw, husk, and grain) of rice plant from an arsenic effected area of West Bengal. Results showed that the level of arsenic in irrigation water (0.05–0.70 mg l−1) was much above the WHO recommended arsenic limit of 0.01 mg l−1 for drinking water. The paddy soil gets contaminated from the irrigation water and thus enhancing the bioaccumulation of arsenic in rice plants. The total soil arsenic concentrations ranged from 1.34 to 14.09 mg kg−1. Soil organic carbon showed positive correlation with arsenic accumulation in rice plant, while soil pH showed strong negative correlation. Higher accumulation of arsenic was noticed in the root (6.92 ± 0.241–28.63 ± 0.225 mg kg−1) as compared to the straw (1.18 ± 0.002–2.13 ± 0.009 mg kg−1), husk (0.40 ± 0.004–1.05 ± 0.006 mg kg−1), and grain (0.16 ± 0.001–0.58 ± 0.003 mg kg−1) parts of the rice plant. However, the accumulation of arsenic in the rice grain of all the studied samples was found to be between 0.16 ± 0.001 and 0.58 ± 0.003 mg kg−1 dry weights of arsenic, which did not exceed the permissible limit in rice (1.0 mg kg−1 according to WHO recommendation). Two rice plant varieties, one high yielding (Red Minikit) and another local (Megi) had been chosen for the study of arsenic translocation. Higher translocation of arsenic was seen in the high yielding variety (0.194–0.393) compared to that by the local rice variety (0.099–0.161). An appreciable high efficiency in translocation of arsenic from shoot to grain (0.099–0.393) was observed in both the rice varieties compared to the translocation from root to shoot (0.040–0.108).  相似文献   

14.
While plant growth and productivity are known to derive from the interaction between genetic potential (G) and environmental factors (E), efforts to improve rice production have usually proceeded assuming a standard E that is created by conventional rice-growing practices. Genotypes have been assessed for their performance in continuously flooded paddy soils, with optimally dense plant populations, with reliance on inorganic fertilization to raise yields. The System of Rice Intensification (SRI) developed in Madagascar and now becoming accepted in much of Asia proposes that GxE interactions can be made more productive with different management practices: optimally sparse populations, established with very young seedlings carefully transplanted, intermittent flooding of paddies, with active soil aeration and with soil organic matter enhanced as much as possible. This article evaluates the effects of alternative SRI cultural practices on grain yield with particular attention to their impact on the growth and functioning of rice plant roots and on associated nutrient-use efficiencies that could be contributing to the observed higher grain yields. On-station experiments and on-farm surveys were conducted in Madagascar to evaluate SRI practices in comparison with standard cultural methods, considering how rice plants’ expression of their genetic potential was affected by different crop management practices. Controlling for both soil and farmer effects, rice plants cultivated with SRI methods produced average yields more than double those from standard practice (6.26 vs. 2.63 t ha−1). The most evident phenotypic difference was in plant root growth, assessed by root-pulling resistance (RPR), a summary measure of root system development. On average, uprooting single SRI plants required 55.2 kg of force plant−1, while pulling up clumps of three conventionally grown plants required 20.7 kg hill−1, or 6.9 kg plant−1. SRI plants thus offered 8 times more resistance per plant to uprooting. Direct measurements confirmed that SRI methods induced both greater and deeper root growth, which could be contributing to increased nutrient uptake throughout the crop cycle, compared with the shallower rooting and shorter duration of root functioning under continuous flooding. Rice plants grown with SRI methods took up more macronutrients than did the roots of conventionally managed plants, which was reflected in the higher SRI yields. When grain yield was regressed on nutrient uptake to assess nutrient-use efficiency, SRI plants achieved higher grain yield per unit of N taken up, compared to plants grown with conventional methods. The internal efficiency (IE) of SRI plants in utilizing macronutrients was 69.2 for N, 347.2 for P, and 69.7 for K, while the IE in plants conventionally grown was 74.9, 291.1, and 70.4 for these three macronutrients, respectively. Although no significant differences in IE were observed for N and K, the uptake of P was significantly greater, indicating more efficient use of P by SRI plants for grain production. More research needs to be done on such relationships, but this study indicates that productive changes in the structure and functioning of rice plants, particularly their roots, can be induced by alternative management methods.  相似文献   

15.
水稻是耗水第一大作物。发展节水栽培对稻田水分高效利用和缓解我国水资源短缺具有重要意义。水稻根系是吸收水分和养分的重要器官，也是多种激素、氨基酸和有机酸合成的重要部位。水分管理措施的改变会直接或间接引起根系生长发育发生改变，从而影响水稻地上部生长发育和产量形成。本文综述了干湿交替灌溉、控制灌溉和覆盖旱种对水稻根系形态和生理特性的影响，提出了今后节水灌溉下水稻根系的研究重点，以期为改善水稻根系形态生理和高产节水栽培提供理论依据。  相似文献   

16.
The system of rice intensification (SRI) developed in Madagascar has been controversial in part because there have been no large-scale, long-term evaluations of the impact of its alternative methods. This paper summarizes experience with the dissemination of SRI practices across eight provinces in Eastern Indonesia over nine seasons from 2002 to 2006 under a major irrigation project. The Decentralized Irrigation System Improvement Project (DISIMP) was financed by the Japanese Government with project management by a Nippon Koei consultant team. SRI has been introduced in Indonesia via several organizations and in different parts of the country starting in 2000. The evaluation reported here, made by the DISIMP technical assistance team, is based on data from 12,133 on-farm comparison trials that covered a total area of 9,429 ha. Under SRI management, average paddy yield increase was 3.3 t/ha (78%). This was achieved with about 40% reduction in water use, 50% reduction in chemical fertilizer applications, and 20% lower costs of production. The farmers whom DISIMP was assisting to take up SRI were usually cultivating their paddy fields individually within irrigation systems where it was difficult to reduce water applications as recommended for SRI. Accordingly, innovations had to be made in soil and water management to create relatively aerobic soil conditions so that farmers could get the more productive rice phenotypes expected from SRI practice. This article describes the modifications made to adapt SRI concepts, pointing to the value of introducing in-field ditches, which was confirmed through paddy tract surveys. This experience and analysis showed how SRI methods could be utilized within irrigation systems where water management was not (yet) tailored to SRI production practices. Subsequently, modifications in irrigation system management are being made to be more supportive of SRI cultivation.  相似文献   

17.
主要节水灌溉方式对水稻根系形态生理的影响   总被引：2，自引：0，他引：2  
水稻是耗水第一大作物。发展节水栽培对稻田水分高效利用和缓解我国水资源短缺具有重要意义。水稻根系是吸收水分和养分的重要器官,也是多种激素、氨基酸和有机酸合成的重要部位。水分管理措施的改变会直接或间接引起根系生长发育发生改变,从而影响水稻地上部生长发育和产量形成。本文综述了干湿交替灌溉、控制灌溉和覆盖旱种对水稻根系形态和生理特性的影响,提出了今后节水灌溉下水稻根系的研究重点,以期为改善水稻根系形态生理和高产节水栽培提供理论依据。  相似文献   

18.
Crop management plays an important role in the transition from a deepwater rice to a flooded rice production system but information about optimum management strategies are currently lacking. The goal of this study was to determine the effect of planting date and variety on flooded rice production in the deepwater area of Thailand. Two experiments were conducted at the Bang Taen His Majesty Private Development Project in 2009 and 2010 to represent conditions prior to flooding (early rainy season) and after flooding (dry season). The early rainy season crop covered the period from May to October 2009, while the dry season crop covered the period from November 2009 to April 2010. The experimental design was a split plot with four main plots and three sub plots replicated four times. The treatments for the main plot were various planting dates, while the treatments for the sub plots were rice varieties. The dates of the critical developmental phases of rice were recorded and biomass was sampled during the growing period. The collected data were statistically analyzed using ANOVA and treatment means were compared to identify the appropriate plating date and the best variety for the area. The highest average yield was obtained for variety PSL2 across transplanting dates from June 19 to July 23, with an average yield of 3898 kg ha−1. The dry season crop showed that both biomass and yield were affected by the interaction between planting date and variety. The highest yield was obtained for variety PTT1 transplanted on November 9. The research showed that the variety PSL2 is the most suitable variety for early rainy season production with a transplanting date ranging from June 19 to July 23, while the variety PTT1 planted on November 9 was the best management practice for the dry season crop. However, a high yielding flooded rice variety that has a short growth duration is still needed for this area.  相似文献   

19.
While many water-saving rice production techniques have been adopted in China, the environmental effects of these techniques require further investigation. This study aims to assess nitrogen (N) and phosphorus (P) leaching losses under real conditions in different water and N managements. Two water and three N treatments are conducted in the Taihu Lake region of China. Results show that the total N leaching losses during the rice season under flooding irrigation (FI) are 12.4, 9.31, and 7.17 kg ha−1 for farmers’ fertilization practices (FFP), site-specific N management (SSNM), and controlled-release nitrogen fertilizer management (CRN), respectively. Under controlled irrigation (CI), the respective losses were 7.40, 5.86, and 3.79 kg ha−1 for the same management methods. The total P leaching losses during the rice season under FI were 0.939, 0.927, and 0.353 kg ha−1 for FFP, SSNM, and CRN, respectively. Under CI, the losses were 0.424, 0.433, and 0.279 kg ha−1, respectively, for the same management methods. Ammonium and nitrate N accounted for 42.2–65.5% and 11.8–14.7% of the total nitrogen leaching losses under different water and N management methods, respectively. Due to significant decrease of volumes of percolation water and nitrogen and phosphorus concentrations in percolation water, N and P leaching losses were reduced in the CI treatment compared to the FI treatment under the same N management. The reduction of N input and application of controlled-release nitrogen fertilizer can reduce N and P leaching losses from paddy fields.  相似文献   

20.
Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying(DSR-AWD) in comparison with direct seeded rice at field capacity(DSRFC). Seed priming treatments were osmo-priming with KCl(2.2%), Ca Cl2(2.2%) and moringa leaf extracts(MLE, 3.3%) including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with Ca Cl2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with Ca Cl2 in DSRAWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or Ca Cl2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or Ca Cl2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.  相似文献   

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