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1.
Field experiments were carried out at the research farm of ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India, during Kharif (June–October) seasons of 2011 and 2012 to study the effect of rice varieties and iron fertilization on water productivity, nutrient uptake and quality of aerobic rice. Treatments comprised of two rice varieties (PRH-10 and PS-5) and eight sources and modes of iron fertilization—control (no iron), iron sulphate @ 50 kg/ha + one foliar spray of 2.0% iron sulphate, iron sulphate @ 50 kg/ha + one foliar spray of 0.5% iron chelate, iron sulphate @ 100 kg/ha, two foliar sprays of 2.0% iron sulphate, three foliar sprays of 2.0% iron sulphate, two foliar sprays of 0.5% iron chelate and three foliar sprays of 0.5% iron chelate. Study results indicated that variety PRH-10 had higher concentration and uptake of nitrogen, phosphorus, potassium and iron than PS-5 variety in grain, straw and grain + straw. Three foliar sprays of 2.0% iron sulphate or 0.5% iron chelate favoured higher NPK and iron concentration and uptake in grain and straw of aerobic rice. Grain quality in respect of hulling, milling and head rice recovery was, however, superior in PS-5 than PRH-10. But the protein content was significantly higher in PRH-10 than in PS-5. Application of three foliar sprays of 2% iron sulphate and three foliar sprays of 0.5% iron chelate recorded significantly higher hulling, milling and head rice recovery as compared to control and remained statistically similar with each other. Irrigation and total water productivity was substantially higher in PRH-10 over PS-5. Growing of rice with PRH-10 recorded ~7.7% higher total water productivity as compared to PS-5, across iron fertilizations. Three or two foliar sprays of 2.0% iron sulphate or 0.5% iron chelate favoured higher irrigation and total water productivity of aerobic rice over control (no iron). 相似文献
2.
Biswanath Dari Debjani Sihi Santanu Kumar Bal Sanju Kunwar 《Paddy and Water Environment》2017,15(2):395-401
Rice (Oryza sativa L.) is the most important staple food crop in the southern region of Asia, and Indian subcontinent being one of the major producers. Production of conventional transplanted rice requires a large amount of irrigation water, labor, and energy. The scarcity of irrigation water has encouraged farmers to adopt an alternative rice production system, i.e. the direct-seeded rice (DSR), which is proposed to be farmers’ friendly with a potential to save water. Our study reports the performance of DSR with respect to yield and water expense efficiency based on different irrigation regimes and dates of sowing. A field experiment was conducted in the semi-arid region of northern India during the rainy season of 2011 with two treatment combinations (dates of sowing: 15th May and 5th June and three irrigation regimes: irrigation scheduled at irrigation water-to-cumulative potential evapotranspiration; IW/CPE ratio of 1.0, 1.5 and 2.0) in a completely randomized design. We found statistically higher water expense efficiency of DSR sown on 5th June as compared to DSR sown on 15th May without any significant differences in growth and yield. A significant yield difference between DSR grown with irrigation regimes of IW/CPE 1.0 and 1.5 and DSR grown with irrigation regimes of IW/CPE ratio 2.0 were observed. The DSR grown with irrigation regimes of IW/CPE ratio of 1.5 resulted in significantly higher water expense efficiency than the one with IW/CPE ratio of 2.0. Obtaining a higher yield of DSR under scarce irrigation water might be a trade-off between optimum water use and maximum yield avoiding excess ground water exploitation in sub-tropical semi-arid regions of India. Our study suggests that sowing time and irrigation regimes are two important aspects of “rice production” to attain “win–win” solution. Thus, strategic and judicial use of irrigation water with management of sowing time could potentially escalate the rice production in water scarce regions of India. 相似文献
3.
W. B. Collins 《American Journal of Potato Research》1977,54(7):339-352
The basis of difference in field growth and yield in Netted Gem potato plants grown from greenhouse transplants, from seed which was greensprouted for two weeks prior to planting and from seed which was retained in storage until planting was studied by measuring changes in plant dry weight and leaf area throughout the season. Cut seed, approximately 70g in size, which were either two or four-cut from 142g or 283g mother tubers respectively, were used in the comparisons. Transplants were started in 7.6 cm peat pots in the greenhouse and were transplanted to the field when 10 cm high. The greensprouted seed was cut from mother tubers which had been sprouted under fluorescent light at 15–18°C for two weeks producing strong sprouts 5 mm long. Transplants, greensprouted seed and seed from mother tubers held in 3°C storage were all planted in the field May 30, 1974, coinciding with commercial plantings of Netted Gem in the province. Backup field experiments, comparing similarly treated greensprouted and storage seed and transplants, were conducted in 1974 and 1975 but were not subjected to growth analysis. All plantings were grown on a Riverbank sandy loam soil. The 1974 growing season in New Brunswick was excellent while that for 1975 was dry and required extensive irrigation. The use of transplants established a substantial advantage in terms of early emergence and yields were consistently and significantly greater than those of greensprouted-seed and unsprouted-seed plants. The transplant yield advantage was attributed to the fact that tuberization was advanced substantially compared with the latter two types. Higher relative growth rates were associated with later emergence so that the rate for plants growing from unsprouted seed was greater than that for plants growing from greensprouted plants which, in turn, was superior to that of transplants. This pattern was maintained through the season. Consequently, small advantages in time of emergence, such as that obtained with greensprouted-seed plants, were not accompanied by significant yield differences. Canopy size decreased as emergence was delayed and canopy size differences were determined largely by the amount of branching. As canopy size decreased and emergence was delayed, the net assimilation rate was found to increase. 相似文献
4.
Growth, yield and water productivity of zero till wheat as affected by rice straw mulch and irrigation schedule 总被引:1,自引:0,他引:1
Intensive cultivation of rice and wheat in north-west India has resulted in air pollution from rice straw burning, soil degradation and declining groundwater resources. The retention of rice residues as a surface mulch could be beneficial for moisture conservation and yield, and for hence water productivity, in addition to reducing air pollution and loss of soil organic matter. Two field experiments were conducted in Punjab, India, to study the effects of rice straw mulch and irrigation scheduling on wheat growth, yield, water use and water productivity during 2006-2008. Mulching increased soil water content and this led to significant improvement in crop growth and yield determining attributes where water was limiting, but this only resulted in significant grain yield increase in two instances. There was no effect of irrigation treatment in the first year because of well-distributed rains. In the second year, yield decreased with decrease and delay in the number of irrigations between crown root initiation and grain filling. With soil matric potential (SMP)-based irrigation scheduling, the irrigation amount was reduced by 75 mm each year with mulch in comparison with no mulch, while maintaining grain yield. Total crop water use (ET) was not significantly affected by mulch in either year, but was significantly affected by irrigation treatment in the second year. Mulch had a positive or neutral effect on grain water productivity with respect to ET (WPET) and irrigation (WPI). Maximum WPI occurred in the treatment which received the least irrigation, but this was also the lowest yielding treatment. The current irrigation scheduling guidelines based on cumulative pan evaporation (CPE) resulted in sub-optimal irrigation (loss of yield) in one of the two years, and higher irrigation input and lower WPI of the mulched treatment in comparison with SMP-based irrigation scheduling. The results from this and other studies suggest that farmers in Punjab greatly over-irrigate wheat. Further field and modelling studies are needed to extrapolate the findings to a wider range of seasonal and site conditions, and to develop simple tools and guidelines to assist farmers to better schedule irrigation to wheat. 相似文献
5.
Crop and water productivity as influenced by rice cultivation methods under organic and inorganic sources of nutrient supply 总被引:1,自引:0,他引:1
Y. V. Singh 《Paddy and Water Environment》2013,11(1-4):531-542
A field experiment was conducted during the wet seasons of 2010 and 2011 at New Delhi, India to study the influence of organic, inorganic, and integrated sources of nutrient supply under three methods of rice cultivation on rice yield and water productivity. The experiments were laid out in FRBD with nine treatment combinations. Treatment combinations included three sources of nutrient supply viz., organic, integrated nutrient management, and inorganic nutrition and three rice production systems viz., conventional transplanting, system of rice intensification (SRI) and aerobic rice system. Results indicated that the conventional and SRI showed at par grain and straw yields but their yields were significantly higher than aerobic rice. Grain yield under organic, inorganic and integrated sources of nutrient supply was at par since the base nutrient dose was same. Plant growth parameters like plant height, tillers, and dry matter accumulation at harvest stage were almost same under conventional and SRI but superior than aerobic rice system. Root knot nematode infestation was significantly higher in aerobic rice as compared to SRI and conventional rice. However, organic, inorganic and integrated sources of nutrient supply did not affect nematode infestation. There was significant advantage in term of water productivity under SRI over conventional transplanted (CT) rice and less quantity of water was utilized in SRI for production of each unit of grain. A water saving of 34.5–36.0 % in SRI and 28.9–32.1 % in aerobic rice was recorded as compared to CT rice. 相似文献
6.
通过对中香1号不同播、抛、栽期对比试验研究,初步掌握了中香1号在湘潭适宜的播种期,抛秧期和移栽期,研究表明,中香1号秧龄弹性大,湿润育秧6月20日前播种,7月22日前移栽,软盘育秧6月18日前播种,7月20日前抛秧,均能正常抽穗结实,但适当早播,早抛(插)有利于高产。 相似文献
7.
Summary Leaf stomatal resistance varies considerably in response to changes in environmental conditions. Understanding cultivar differences
in the response of stomata to these conditions is important for effectively simulating water-use and growth.
In this study the stomatal resistance of three field grown potato (Solanum tuberosum L.) cultivars Atlantic. Monona and Norchip was observed in response to photosynthetic photon flux density, leaf to air vapour
pressure difference and root zone available soil water. Substantial variation in stomatal resistance was accounted for by
functions of the environmental variables for both Monona and Norchip. The explained variation for Atlantic was considerably
less. Light saturation occurred near 500 μmol m−2 s−1. Increasing stomatal resistance above 1000 μmol m−2s−1 was also observed but is likely an artifact of stomatal closure on days in which mid-day leaf water potentials dropped below
critical levels. Although the leaf presumably insufficient to obtain substantial effects. The soil water status was partially
linked to the average 1000 h to 1500 h stomatal resistance on clear, sunny days. Significant differences were observed among
the cultivars in the response of stomata to changes in the available soil water. 相似文献
8.
9.
A study was conducted on sand and loam soils to evaluate the response of three potato cultivars to subsoiling and irrigation frequency. Subsoiling was of little benefit on the loam soil. On the sand, subsoiling promoted deep rooting and allowed potatoes to avoid water stress usually associated with four days between irrigations. Russet Burbank was much more sensitive to water stress than was Nooksack or Lemhi, especially in the percentage of tubers not graded U.S. No. 1. Benefits from subsoiling may be inadequate to justify the cost if a reliable high-frequency irrigation system is available. 相似文献
10.
Wheat quality and productivity as affected by varieties and sowing time in Haryana, India 总被引:2,自引:0,他引:2
D.R. Coventry R.K. GuptaA. Yadav R.S. PoswalR.K. Sharma V.K. YadavS.C. Gill A. KumarA. Mehta S.G.L. KleemannA. Bonamano J.A. Cummins 《Field Crops Research》2011,123(3):214-225
Of the wheat grown in North-West India the majority is consumed as traditional Indian flat bread (chapatti). Chapatti quality is important to consumers and people are willing to pay more for better quality wheat flour, but farmers do not specifically target quality outcomes as the majority of their wheat is sold with no segregation. For farmers the main objective is to harvest maximum yields, but in the last decade productivity growth for wheat yields has slowed in the areas where the wheat is grown in a double cropping pattern. Nutrient depletion and temperature-related stress are possible causes for this decline in productivity growth. Farmers meanwhile are looking to opportunities to maintain profitability and, with consumers willing to pay a higher price for better chapatti wheat, an opportunity exists for farmers to manage their wheat to improve both the yield as well as quality of wheat. In this paper we evaluate management practices that best achieve high yield and better chapatti quality, and assess the temperature environment for the winter wheat growing season. A step-wise analysis of the long-term temperature trend for sites in NW India showed that mean annual temperature has increased by 0.7-1.0 °C during the last decade. Field experiments with wheat varieties (C-306, WH-283, DBW-17, PBW-343, PBW-502, PBW-550, Raj-3765 and WH-1025) were conducted at farmers’ fields under 4 different sequential cropping rotations for the 2007-08 and 2008-09 winter seasons in Haryana (India). C-306 and WH-283 are varieties with excellent chapatti quality but are lower yielding by 15-26% than the more widely grown varieties such as PBW-343 and PBW-502. The replicated experiments involved three sowing times, these being an early sowing (late October to early November, timely sowing (mid November) and a late sowing (early December). A differential response of varieties was observed to sowing time with the yield of C-306 better whereas that of WH-283 and Raj-3765 was poor in early sown conditions. The varieties DBW-17, PBW-343 and PBW-502 were the highest yielding wheat with similar performance under early as well as timely sowing. All the varieties had lowest yield in December sowing. In general, late sowing had lower thousand grain weight but higher protein content. Of the quality measure grain hardness was the only attribute with a consistent positive correlation with chapatti quality. The chapatti score was higher for varieties C-306 and WH-283 compared to the other varieties but grain hardness and chapatti score was not much affected by sowing time. With all varieties included in the analysis there was no correlation between protein and chapatti score, but within an individual variety usually higher protein resulted in a higher chapatti score. There was no association of grain test weight or sedimentation value with chapatti score. From the results shown here it is evident that farmers will be able to manage with variety choice and timely sowing to obtain chapatti quality without losing grain yield benefits. 相似文献
11.
Peng Jiang Xiaobing Xie Min Huang Xuefeng Zhou Ruichun Zhang Jiana Chen 《Plant Production Science》2016,19(1):96-104
To compare N uptake and use efficiency of rice among different environments and quantify the contributions of indigenous soil and applied N to N uptake and use efficiency, field experiments were conducted in five sites in five provinces of China in 2012 and 2013. Four cultivars were grown under three N treatments in each site. Average total N uptake was 10–12 g m?2 in Huaiji, Binyang, and Haikou, 20 g m?2 in Changsha, and 23 g m?2 in Xingyi. Rice crops took up 54.6–61.7% of total plant N from soil in Huaiji, Binyang, and Haikou, 64.3% in Changsha, and 63.5% in Xingyi. Partial factor productivity of applied N and recovery efficiency of applied N in Changsha were higher than in Huaiji, Binyang, and Haikou, but were lower than in Xingyi. Physiological efficiency of soil N and fertilizer N were lower in Changsha than in Huaiji, Binyang, and Haikou, while the difference in them between Changsha and Xingyi were small or inconsistent. Average grain yields were 6.5–7.5 t ha?1 (medium yield) in Huaiji, Binyang, and Haikou, 9.0 t ha?1 (high yield) in Changsha, and 12.0 t ha?1 (super high yield) in Xingyi. Our results suggest that both indigenous soil and applied N were key factors for improving rice yield from medium to high level, while a further improvement to super high yield indigenous soil N was more important than fertilizer N, and a simultaneous increasing grain yield and N use efficiency can be achieved using SPAD-based practice in rice production. 相似文献
12.
13.
In water-efficient rice production, grain yield is often constrained by panicle size. The objective of this study was to genetically dissect the response of panicle morphology to irrigation regimes in aerobic rice culture. We grew ‘Akihikari’ (a lowland japonica cultivar) × ‘IRAT109’ (an upland japonica cultivar) backcross inbred lines in aerobic soils with full or limited irrigation for 2 years, and examined 4 panicle traits—number of florets per panicle (FPP), number of primary branches per panicle (BPP), number of florets per primary branch (FPB), and frequency of pre-flowering floret abortion (%FA)—and grain yield. QTLs for BPP were detected in both the irrigation regimes but QTLs for FPB and %FA were detected mostly only in either of the irrigation regimes. The QTL for FPP on chromosome 2 (RM3421–RM213) coincided with that for yield under full irrigation, showing that this QTL is related to sink capacity and yield potential in aerobic rice culture. On the other hand, the QTL for FPB on chromosome 1 (RM3148–RM243) coincided with that for yield under limited irrigation, when water deficit was moderate. The QTL for root axis length at vegetative stage, previously identified in the same mapping population, was located near this region. This study unravelled the complicated genetic control on panicle morphology in aerobic rice culture, and suggested the positive roles of the dehydration avoidance mechanism by vigorous root growth on panicle size and yield under dry soil conditions. 相似文献
14.
A compact subsoil restricts rooting and reduces the volume of soil from which plant roots can obtain water and nutrients. A reduced water supply may result in severe plant water stress between irrigations. A study was conducted on a sandy soil to evaluate the responses of three early potato cultivars (Norgold Russet, HiLite Russet, and Russet Norkotah) to subsoiling to loosen a compact subsoil and to four irrigation regimes. Differences among cultivar responses to irrigation and subsoiling treatments were minor. All performed best with daily irrigation to replace évapotranspiration (ET) and poorest when irrigation was interrupted during tuber bulking. With daily irrigation to replace ET, subsoiling had little benefit, but with inadequate irrigation, subsoiling improved yield and quality of tubers compared to not subsoiling. Averaged over all treatments, HiLite was the lowest yielding cultivar and had the least U.S. No. 1 and the most undersize tubers. Norkotah had the most U.S. No. 1 and the fewest undersize tubers. 相似文献
15.
Romeo J. Cabangon To Phuc Tuong Ernesto G. Castillo Lang Xing Bao Guoan Lu Guangho Wang Yuanlai Cui Bas A. M. Bouman Yuanhua Li Chongde Chen Jianzhang Wang 《Paddy and Water Environment》2004,2(4):195-206
Alternate wetting and drying irrigation (AWD) has been reported to save water compared with continuous flooding (CF) in rice cultivation. However, the reported effects on yield varied greatly and detailed agro-hydrological characterization is often lacking so that generalizations are difficult to make. Furthermore, it is not known how AWD modifies nutrient use efficiencies and if it requires different N-fertilizer management compared with CF. This study quantified the agro-hydrological conditions of the commonly practiced AWD and compared the impact of AWD and CF irrigations at different N-fertilizer management regimes on rice growth and yield, water productivity, and fertilizer-use efficiencies in five crop seasons in 1999 and 2000 at two typical lowland rice sites in China (Jinhua, Zheijang Province and Tuanlin, Hubei Province), with shallow groundwater tables.Grain yields varied from 3.2 to 4.5 t ha–1 with 0 kg N ha–1 to 5.3–8.9 t ha–1 with farmers N-rates (150 kg N ha–1 in Jinhua and 180 in Tuanlin). In both sites, no significant water by nitrogen interaction on grain yields, biomass, water productivity, nutrient uptakes and N-use efficiency were observed. Yield and biomass did not significantly differ (P >0.05) between AWD and CF and among N timings. The productivity of irrigation water in AWD was about 5–35% higher than in CF, but differences were significant (P <0.05) only when the rainfall was low and evaporation was high. Increasing the number of splits to 4–6 times increase the total N uptake, but not total P-uptake, and total K-uptake compared with farmers practices of two splits. Apparent Nitrogen recovery (ANR) increased as the number of splits increased, but there was no significant difference in ANR between AWD and CF. During the drying cycles of AWD irrigation, the perched water table depths seldom went deeper than – 20 cm and the soil in the root zone remained moist most of the time. The results suggest that in typical irrigated lowlands in China, AWD can reduce water input without affecting rice yields and does not require N-fertilizer management differently from continuous flooding. The results can be applied to many other irrigated lowland rice areas in Asia which have a shallow groundwater table. 相似文献
16.
Amod Kumar Thakur Rajeeb Kumar Mohanty Dhiraj U. Patil Ashwani Kumar 《Paddy and Water Environment》2014,12(4):413-424
The system of rice intensification (SRI) reportedly enhances yield with less water requirement. This claim was investigated to determine the effects of alternative cultivation methods and water regimes on crop growth and physiological performance. Treatment combinations compared SRI with the conventional transplanting system (CTS) using standard practices, evaluating both along a continuum from continuous flooding to water applications at 1, 3, 5, or 7 days after disappearance of ponded water (DAD), subjecting plants to differing degrees of water stress while reducing total water expenditure. SRI methods gave significant changes in plants’ phenotype in terms of root growth and tillering, with improved xylem exudation and photosynthetic rates during the grain-filling stage compared to CTS. This resulted in significant increases in panicle length, more grains and more filled grains panicle?1, greater 1,000-grain weight, and higher grain yield under SRI management. Overall, averaged across the five water regimes evaluated, SRI practice produced 49 % higher grain yield with 14 % less water than under CTS; under SRI, water productivity increased by 73 %, from 3.3 to 5.7 kg ha-mm?1. The highest CTS grain yield and water productivity were with the 1-DAD treatment (4.35 t ha?1 and 3.73 kg ha-mm?1); SRI grain yield and water productivity were the greatest at 3-DAD (6.35 t ha?1 and 6.47 kg ha-mm?1). 相似文献
17.
The System of Rice Intensification (SRI), developed in Madagascar almost 30 years ago, modifies certain practices for managing
plants, soil, water, and nutrients with the effect of raising the productivity of the land, labor, and capital devoted to
rice production. Certain production inputs are reduced—seeds, inorganic fertilizer, water, and fuel where water is pumped—with
increased yield as a result. This paper introduces the subject of SRI, which is then addressed variously in the articles that
follow. SRI is gaining interest and application in over 40 countries around the world. Its practices make soil conditions
more aerobic and promote greater root growth, as well as larger, more diverse communities of beneficial soil biota. These
below-ground changes support more productive phenotypes above-ground for practically all rice genotypes (cultivars) tested
so far, with supportive evidence accumulating both from scientific institutions and field applications. SRI methodology remains
controversial in some circles, however, because of the transformational change it introductions into traditional lowland rice
production systems. This issue of PAWE brings together the results of formal research on SRI in a number of countries (Part
I) and also reports on initiatives by government agencies, NGOs, universities, or the private sector, bringing knowledge of
SRI to farmers in a wide range of agroecological circumstances (Part II). This introduction presents the basic principles
that underlie SRI and discusses the nature of this innovation as well as considers some of the issues in contention. SRI continues
to evolve and expand, being a work in progress. Its concepts and methods are being extended also to upland (rainfed) rice
production, as well to other crops. Accordingly, SRI should not be regarded or evaluated in conventional terms as if it were
a typical component technology. It is understood more appropriately in terms of a paradigm shift for rice production. In particular,
it calls into question the long-standing belief that rice is best produced under continuously flooded conditions. 相似文献
18.
Variation in rice quality of different cultivars and grain positions as affected by water management 总被引:13,自引:0,他引:13
Wangda Cheng Guoping Zhang Guoping Zhao Haigen Yao Haiming Xu 《Field Crops Research》2003,80(3):245-252
A field experiment was conducted to study the effect of cultivar and grain position on rice quality under different water management treatments. Water treatments significantly affected all quality traits in the study, except alkali digestibility (AD). There were significant interactions of water treatment by grain position and genotype for brown rice rate (BRR), chalky grain rate (CGR) and amylose content (AC), and interactions of grain position by water treatment and cultivar for head milled rice rate (HMRR). The interaction of water treatment by genotype for protein content (PC) was also significant. Of all variance components, water treatment ranked the highest for PC. Similarly grain position was ranked the highest for AC, BRR, CGR and HMRR. In comparison with wet cultivation, plastic-film mulched cultivation had significantly lower BRR, HMRR, CGR and higher PC. There were marked differences in milled quality, appearance and AD among differently positioned grains within a spike. For appearance and PC, the difference between plastic-film mulched cultivation and wet cultivation was greater for upland rice than paddy rice. For milled and cooking–eating quality, the difference between plastic-film mulched cultivation and wet cultivation was greater for the good quality paddy rice than the upland rice and the poor quality paddy rice. In plastic-film mulched cultivation, top grains showed lower milled quality and PC. While in wet cultivation, the opposite result was seen. With the decrease in soil water content, BRR and appearance showed increased and decreased differences among grains within a spike, respectively. The results indicate the possibility of improving rice quality by use of better water management and suitable cultivars. 相似文献
19.
The impact of on-farm water saving irrigation techniques on rice productivity and profitability in Zhanghe Irrigation System,Hubei, China 总被引:3,自引:1,他引:3
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
20.
The effects of irrigation method, age of seedling and spacing on crop performance, productivity and water-wise rice production in Japan 总被引:4,自引:4,他引:0
A field experiment using system of rice intensification (SRI) techniques was conducted in Chiba, Japan during the 2008 rice-growing
season (May–September) with eight treatment combinations in a split–split plot design (S–SPD) to observe the potential of
SRI methods under the temperate climatic conditions in Japan. Intermittent irrigation with alternate wetting and drying intervals
(AWDI) and continuous flooding throughout the cropping season were the two main-plot factors, while the effects of age of
seedlings and plant spacing were evaluated as sub and sub–sub plot factors, respectively. The experiment results revealed
that the proposed AWDI can save a significant amount of irrigation water (28%) without reduced grain yield (7.4 t/h compared
with 7.37 t/h from normal planting with ordinary water management). Water productivity was observed to be significantly higher
in all combinations of practices in the intermittent irrigation plots: 1.74 g/l with SRI management and AWDI as compared to
1.23 g/l from normal planting methods with ordinary water management. In addition, the research outcomes showed a role of
AWDI in minimizing pest and disease incidence, shortening the rice crop cycle, and also improving plant stand until harvest.
Synergistic effects of younger seedlings and wider spacing were seen in tillering ability, panicle length, and number of filled
grains that ultimately led to higher productivity with better grain quality. However, comparatively better crop growth and
yields when using the same SRI practices with ordinary water management underscore a need for further investigations in defining
what constitute optimum wetting and drying intervals considering local soil properties, prevailing climate, and critical watering
stages in rice crop management. 相似文献