Water-saving Irrigation Modes Research Articles

Microbial community structure and function in paddy soil as affected by water-saving irrigation mode

The objective of this study was to understand how the water-saving irrigation mode affected the microbial community structure and function in paddy soil. A field experiment with three irrigation modes (flooding irrigation FI, alternate wetting and drying irrigation AI and ridge irrigation RI) was conducted, and DNA extracted from the upper 25 cm paddy soils were measured using whole genome sequencing (WGS). The results showed that FI, AI and RI modes were significantly distinct in microbial communities. Compared to FI mode, two water-saving irrigation modes (AI and RI) decreased the relative abundance of Euryarchaeota and showed significant difference in their microbial co-occurrence networks. Compared to FI mode, AI mode increased the relative abundance of Proteobacteria but decreased the relative abundance of Actinobacteria, while RI mode showed opposite effects. Some biomarker species associated with carbon/nitrogen metabolism, such as Cupriavidus taiwanensis, Gemmatirosa kalamazoonesis, Nitrospira moscoviensis, Pseudomonas tolaasii and Methanosarcina barkeri, were significantly sensitive to different irrigation modes. Meanwhile, two water-saving irrigation modes especially AI mode enhanced the genes involved in carbohydrate decomposition and nitrification pathways, while FI mode significantly enriched the genes involved in methane metabolism, denitrification and nitrogen fixation. Thus two water-saving irrigation modes decreased the main methanogen (Methanosarcina barkeri) and methanogenesis genes in paddy soil, while AI mode enhanced potentially beneficial microbes and carbon/nitrogen metabolic-related genes in paddy soil.

Fate of each period fertilizer N in Mollisols under water and N management: A 15N tracer study

For soil-crop systems, it is important to increase the retention of fertilizer N that is not effectively utilized by crops in stable forms in soil and reduce fertilizer N loss from agroecosystems through agricultural practices. However, it remains obscure how the fate of fertilizer N will be affected by water and N management. To further clarify the effects of water and N management on the fate of each period fertilizer N and residual fertilizer N amounts of different derived forms, a field experiment was conducted in Mollisols in Northeast China. This experiment combined a field plot experiment with a flied microplot 15N isotope experiment, and six treatments were performed: two irrigation management modes (controlled irrigation and flooded irrigation) and three fertilizer-N rates (85, 110 and 135 kg/ha). Additionally, the basal, tillering, and panicle fertilizer N were tracked by 15N-labeled urea to study the fate of each period fertilizer N. The present study showed that under controlled irrigation (CI), fertilizer-derived N in different forms increased with the increase N rate. Under flooded irrigation (FI), with the increase N rate, the residual organic nitrogen (NO) first increased and then decreased, and the other forms of fertilizer-derived N increased. In the total residual fertilizer N in soil, residual basal fertilizer N accounted for the highest proportion under the two irrigation modes, residual tillering fertilizer N accounted for the lowest proportion under FI, and panicle fertilizer N accounted for the lowest proportion under CI. NO accounted for the highest proportion of the residual amount of each period fertilizer N under CI and FI, while NO3--N accounted for the lowest proportion under CI, and fixed ammonium accounted for the lowest proportion under FI. Compared with FI, CI increased the total residual fertilizer N amount and promoted the conversion of residual fertilizer N into NO. The present study suggested that CI, as a water-saving irrigation mode, not only decreased agricultural water consumption but also increased fertilizer N retention in soil and enhanced the conversion of residual fertilizer N into NO. The establishment of appropriate water and N management has great potential for the regulation of residual fertilizer N in paddy soil.

Multi-objective optimization of rice irrigation modes using ACOP-Rice model and historical meteorological data

Current rice production in China is associated with low rainfall use efficiency. In order to increase rainfall use efficiency and develop simple water-saving irrigation modes that could be readily implemented by farmers, a new multi-objective optimization framework for irrigation modes of paddy rice was developed, based on a modified version of the AquaCrop model called ACOP-Rice model. The optimization focused on the water level at which irrigation was triggered for five growth periods and the irrigation frequency, rainfall use efficiency and yield were optimized. The procedure was tested on nine rice production cases in China for which over 60 years of historical meteorological data and irrigation guidelines were available. Analysis of the weather data showed that rainfall distribution varied greatly between the different locations and growth periods. The results obtained by following the current guidelines were compared to three optimal solutions that corresponded to minimum number of irrigation events, maximum rainfall use efficiency and “balanced” performance in which equal attention was given to rainfall use efficiency and irrigation frequency, respectively. Overall, the optimization led to lowering the water depth at which irrigation was triggered. The optimal water level after irrigation varied between the different cases, depending on the combined effects of rainfall distribution, operation constraints and length of growth period. Compared to the current guidelines, the optimized irrigation modes reduced the proportion of drainage caused by rainfall after irrigation. For optimal solutions with minimum number of irrigation events, maximum rainfall use efficiency and “balanced” performance, the number of irrigation events was reduced by 57 %, 18 % and 44 % on average (9.4, 3.0 and 7.4 fewer irrigation events per year) while on average rainfall use efficiency improved by 5 %, 19 % and 17 % without significant yield loss.

Research on the Utilization Efficiency of Nitrogen by Winter Wheat under Different Water and Fertilizer Regulation and Cultivation Modes

Since 2016 China liberalized its third-child policy, which resulted in an increase of millions of people every year and therefore China must ensure annual output increases. The utilization efficiency of water and fertilizer is one of the most important keys to mitigating the food crisis. Artificial intelligence technology will be the development of Chinese agriculture. However, the physical and chemical properties of soil, the selection of seeds, the characteristics of different crops, the proportion of water and fertilizer regulation, and the different tillage methods all affect the grain output and the sustainable development of tillage mode. The purpose of this paper is to find the direct relationship between tillage mode and water and fertilizer regulation, and summarize some rules. To provide data and theoretical support for the implementation of China’s modern agriculture. Therefore, winter wheat (wheat breed: Ji wheat 22) as the study crop was targeted, two irrigation methods: traditional irrigation (A) and water-saving irrigation (B) were selected, three fertilization factors: no fertilization (CK), traditional fertilization (FC) and optimized fertilization (FO) were chosen. Water and nitrogen fertilizer were used as control variables. This paper analyzes the environmental benefits of winter wheat irrigation and fertilization and provides a theoretical basis for rotation system efficiency and the sustainable production of winter wheat in a plain area. The results suggested that the water-saving irrigation mode had significantly better nitrate absorption efficiency of soil. The water-saving model is more conducive to improving the nitrogen absorption efficiency by the soil.

Орошение моркови: проблемы и перспективы

Purpose: to study modern approaches to the determination of irrigation regimes and water consumption for carrots during sprinkler irrigation. Discussion. Carrot is a vegetable crop in demand in the modern food market. In Russia, no more than 1–1.5 million tons of carrot root crops are currently cultivated, which covers the country's needs only by 70–80 %. The rest is replenished through imports. Under modern conditions, the increase of the vegetable crops yield, including carrots, is impossible without irrigation. Numerous studies confirm that, along with biological characteristics, climatic and other factors, irrigation affects the carrot yield, significantly increasing it in comparison with rainfed. The analysis of the recent research made it possible to note that the most common method of carrot crops watering is sprinkling. However, this requires significant volumes of irrigation water, and therefore, water-saving irrigation modes are in demand under modern conditions. It is known that the optimal soil water regime on carrot crops is formed when the moisture content is maintained at least 75–80 % HB. The critical period for moisture provision is from the carrots sowing to the appearance of their shoots, as well as the periods of the greatest frondescence and intensive root formation. Conclusions. Water regime management is achieved by irrigation differentiation by the plant growth and development phases, soil moisture regimes, as well as the depth of the wetted layer. The use of this methodological approach helps to reduce the total water consumption, to increase the efficiency of moisture use by crops. Using computational approaches to determine the elements of water balance, which make it possible to control the water regime of carrot crops is promising.

Adaptive abilities of corn hybrids under different irrigation modes and moisture supply in the arid Steppe of Ukraine

Aim. The study presents the results of the research on the productivity features and adaptability parameters of domestic corn hybrids under different irrigation modes and water supply under conditions of the Arid Steppe. Methods. The general scientific, special selection genetic, computational and comparative research methods were used. The research object was modern corn hybrids of domestic selection of different maturity groups. The hybrids were sown under different irrigation modes (common sprinkling, drip irrigation, sub-irrigation). Results. The retrospective analysis of the productivity of main grain crops in the area of the Arid Steppe over a 130-year period showed that the highest rates of an increase in productivity were recorded in corn. An annual increase in its productivity was 31 kg/ha per year and it was due to the use of new varieties (hybrids) and the improvement of growing techniques. Irrigation made it possible to realize potential productivity of new hybrids and increase the productivity from 6.59 to 82.3 c/ha. Productivity rose 12.5 times over a 130-year period, the annual increase being 58 kg/ha per year. Without irrigation the grain productivity was the highest in early-maturing hybrids – 3.28 and 3.05 t/ha indicating their high drought resistance. The use of these hybrids is appropriate under conditions of water-saving irrigation modes on irrigated lands with a low hydro-module and on dry massifs. A fall in the productivity under other irrigation modes was from 0.41 to 1.93 t/ha. Conclusions. Under irrigation conditions it is necessary to use corn hybrids with a genetically programmed reaction to optimal growing conditions (an optimal mode of soil moisture and mineral nutrition).
 Keywords: hybrid, corn, irrigation, adaptability, drought resistance, grain, selection.

Greenhouse Gas Emissions and Global Warming Potential in Double-Cropping Rice Fields as Influenced by Two Water-Saving Irrigation Modes in South China

“Thin-wet-dry” irrigation (TR) and alternate wetting and drying irrigation (DR) are two effective water-saving irrigation modes used for paddy fields. The objectives of this study were to assess the effects of two water-saving irrigation modes on methane (CH4) and nitrous oxide (N2O) emissions from rice fields in the south of the Tropic of Cancer, south China, and verify the hypothesis about the reducing effect of both TR and DR modes on global warming potential (GWP) and greenhouse gas emission intensity (GHGI) compared with conventional irrigation (CR). Three-year field experiments with three irrigation modes were continuously conducted during 2015–2017 to monitor the changes of CH4 and N2O fluxes during the growing period of double-cropping rice, and then the cumulative CH4 and N2O emissions, GWP, and GHGI were analyzed. Compared with CR mode, both TR and DR saved total irrigation amount by 19.5–40.4 and 27.1–52.5% but did not affect the rice yield; DR lowered CH4 emissions from double-cropping rice field over the whole growing period by 41.1–67.0% and TR only reduced CH4 emissions from 2016 late rice field by 31.4%, but TR and DR increased N2O emissions by 57–271 and 79–825%; DR lowered GWP and GHGI by 40.7–66.8 and 48.3–65.5%, and TR declined GWP and GHGI in 2015 and 2016 late rice fields by 31.3–43.4 and 22.4–49.7%. Moreover, rice season significantly influenced GWP and GHGI. Two water-saving irrigation modes reduced GWP and GHGI and our results can provide scientific basis in precisely estimating greenhouse gas emission in China.

CH4 Emission Flux Model in Rice Growing Season in Cold Region Under Water Saving Irrigation Mode

CH4 Emission Flux Model in Rice Growing Season in Cold Region Under Water Saving Irrigation Mode

An Inexact Optimization Model for Crop Area Under Multiple Uncertainties.

This paper developed a type-2 fuzzy interval chance constrained programming model for optimizing a crop area, which integrated chance constrained programming and type-2 fuzzy interval programming. The developed model was then applied to a case study in Wuwei City, Gansu Province, China, and the maximization of economic benefit was selected as the planning objective. Furthermore, different water-saving irrigation modes were considered as the development mode. A series of optimal irrigation water and planting structure schemes were obtained under different violation probabilities in each water-saving scenario. The obtained results could be helpful to make decisions on the planting structure and the optimal use of irrigation water and land resources under multiple uncertainties.

Study on the Law of Nitrogen Transfer and Conversion and Use of Fertilizer Nitrogen in Paddy Fields under Water-Saving Irrigation Mode

The research on the effect of water-saving irrigation technology on the loss of nutrients and chemical substances in farmland has become a hot issue in the field of agricultural water and soil. Based on comparative experiments and combined with the isotope N15 tracer technique, the mechanism of nitrogen migration and transformation and the trend of fertilizer nitrogen use under different irrigation modes were studied. The results showed that water-saving irrigation modes (thin and wet irrigation W1 and intermittent irrigation W2) could reduce the NO3−-N leaching loss by reducing the water leakage amount and the NO3−-N concentration, and effectively inhibit the leaching loss of fertilizer nitrogen. Compared with conventional irrigation (W0), the leaching loss amount of fertilizer nitrogen in W1 and W2 decreased by 62% and 64%, respectively. Under the same amount of fertilizer, water-saving irrigation mode can significantly reduce the total amount of ammonia (NH3) volatilization and the proportion of NH3 volatilization of fertilizer nitrogen in total NH3 volatilization, and significantly increase the nitrogen uptake of rice plants. Meanwhile, water-saving irrigation mode can increase the total nitrogen content of paddy soil by 14.0% but reduce the residual rate of fertilizer nitrogen in soil by 14.6%. Moreover, crop nitrogen uptake can be significantly increased under water-saving irrigation. Compared with W0, the nitrogen fertilizer use rate of W1 and W2 increased by 5.0% and 9.7%, respectively. The research results can provide an important basis for controlling agricultural non-point source pollution, curbing the decline of soil fertility and deterioration of soil quality in paddy fields.

The corps’ growth with different water-saving irrigation conditions in new reclamation areas along the coast of Jiangsu

This study performed a quantitative evaluation of the impact of the corps’ growth with different water-saving irrigation conditions in new reclamation areas along the coast of Jiangsu. In this work, the yield and the amount of irrigation water of corps’ (watermelon, green pepper, and rice) with different water-saving irrigation modes were investigated. The results indicate that the drip-irrigation and micro-spray irrigation can observably reduce the amount of irrigation-water. With respect to normal irrigation, the rate of water-saving is 39.2%. At the same time, there’s been some improvement in the yield of corps. Water-saving irrigation can been accepted as an important means for alleviating the shortage of fresh water resources in the new reclamation.

A review of N2O emissions affected in farmland ecosystem

N2O is an important greenhouse gas in the atmosphere. Agricultural production is the largest source of N2O emissions. The influencing factors of N2O emission from farmland ecosystem, such as soil moisture, soil temperature, soil oxidation-reduction potential, pH of soil, fertilization management and soil texture are summarized, which are closely related to irrigation management. The soil moisture content of drip irrigation, sprinkler irrigation and other water-saving irrigation methods is different. The research on N2O emission from the world’s water-saving irrigation mode has great potential for reducing greenhouse gas emissions. Future work on N2O emissions should carry out the studies on the regulation of greenhouse gas emission by water saving irrigation in different ecological conditions.

Models of corn hybrids of different maturity groups FAO 150–490 for irrigated conditions

Purpose. To substantiate morphophysiological and heterozosis models of high yield hybrids of maize FAO 150–490 for irrigation conditions and to create appropriate genotypes with specific adaptability to agroecological factors.Methods. The general scientific, special selection genetic, computational and comparative research methods were used.Results. The results of long-term study of maize hybrid models of different maturity groups within the conditions of irrigation are presented. The basic parameters of maize hybrid models of different FAO groups were determined. The parameters of heterozosis models are determined and the lines with high combining ability were created, which are involved in the pedigree of early-ripening, early ripe medium, mid-ripening, middle-late and late groups of maturity of newly created hybrids. The results of the new hybrids response to irrigation methods and regimes are presented. It was found that FAO 190 hybrids have stable yields independently of different irrigation modes. The use of these hybrids is appropriate for the water-saving irrigation modes on irrigated lands with a low groundwater line. Among the middle-hybrids (FAO 300–390) the strong reaction in hybrids growing environmental gradient has appeared. The yield of this hybrids type falls dramatically under water-saving irrigation modes. There were defined corn hybrids of intensive type ‘Arabat’, ‘DN Getera’, ‘DN Anchlag’, ‘DN Rava’ in medium-late hybrid group which provide corn yield of 15–17 t/ha during the drip irrigation and sprinkling irrigation within Ingulets and Kahovsky irrigated lands. There is no practical need to grow this type of hybrids on irrigated lands with a low groundwater line and water-saving condition as far as this type of technology leads to the strong yield loss therefore they become non-competitive with modern FAO 190–290 hybrids.Conclusions. There new innovative FAO maize hybrids 150–490 were created for irrigated cultivation on the south of Ukraine, which are possessing a complex of economic and valuable features and are able to form high yields during the irrigation (11–17 t/ha). The differentiating ability of the environment within high soil fertility is more than in close-extreme conditions where environmental factors cause a leveling effect on the phenotype’s signs implementation of FAO 400–490 hybrids. The morpho-biological features that determine corn yield are steadily implemented only at high soil fertility. For this reason the phenotype selection is reliable only in favorable conditions. The flexible hybrids adapted to a wide range of external conditions within irrigation’s intensive technologies give way to genotypes productivity with a narrow adaptability.

Study on model of greenhouse gas N<SUB align="right">2O emission flux of rice field in cold region in growing season in water-saving irrigation mode

Under the condition of field experiment, three water management modes of control irrigation, intermittent irrigation and flood irrigation were set, a static black-box-gas chromatographic method was adopted for field in-situ observation on N2O emission flux of cold region rice field in the growing season, and optimal single-factor model and interaction model of N2O emission flux of rice in different water management modes in the growing season were established by using test data of 2014. The interaction model can effectively describe the response features of rice field N2O emission flux to soil nitrate nitrogen and temperature coordinated variation better than any single-factor model. The models of the study can be used for estimating N2O emission flux of rice field in the growing season in cold region of China.

Study on model of greenhouse gas N2O emission flux of rice field in cold region in growing season in water-saving irrigation mode

Under the condition of field experiment, three water management modes of control irrigation, intermittent irrigation and flood irrigation were set, a static black-box-gas chromatographic method was adopted for field in-situ observation on N2O emission flux of cold region rice field in the growing season, and optimal single-factor model and interaction model of N2O emission flux of rice in different water management modes in the growing season were established by using test data of 2014. The interaction model can effectively describe the response features of rice field N2O emission flux to soil nitrate nitrogen and temperature coordinated variation better than any single-factor model. The models of the study can be used for estimating N2O emission flux of rice field in the growing season in cold region of China.

Water-saving irrigation modes based on water supply and demand of winter wheat and summer maize

节水灌溉是解决水资源短缺问题的重要途径之一。在长期田间试验的基础上, 运用Hydrus-1D模型对研究区冬小麦 夏玉米轮作条件下的田间水分运移过程进行了模拟分析, 探讨适宜的节水灌溉模式。结果表明, 表征土壤水分实测值与模拟值精度关系的Nash-Suttcliff效率系数Ens为0.652~0.903, 均大于0.5, 模型效果良好; 在灌水量为520 mm的传统灌溉模式下, 1.6 m土层深层土壤水分无效渗漏量为189 mm, 占地表总入渗补给水量的22.3%, 土壤水分无效渗漏大, 且与降雨和灌溉关系密切; 根据作物水分供需状况及土壤水分状况得出夏玉米、冬小麦季的灌溉量分别为50 mm、320 mm, 比传统灌溉模式共节水100 mm。改进后的灌溉模式对于土壤水分渗漏具有良好的控制作用, 土壤水分渗漏峰值明显降低, 根据作物供需与土壤水分状况提出的节水灌溉模式能减少土壤水分渗漏, 提高灌溉水利用效率。

The Optimal Choice of Water Saving Irrigation Mode

Using the analytic hierarchy theory and method to evaluate the related project for optimal selection of water-saving irrigation in the area of Xiaoshan in Zhejiang province. Establish the analysis model of optimal irrigation level and get the total ordering of water saving irrigation mode. Ultimately choose the sprinkling irrigation as the optimal irrigation.

Lasting effects of controlled irrigation during rice-growing season on nitrous oxide emissions from winter wheat croplands in Southeast China

Nitrous oxide (N2O) emission from croplands in China is a serious environmental concern. Water management is an important factor in regulating N2O emissions from croplands. In China, controlled irrigation (CI) is one mode of the water-saving irrigation for rice and is widely used. This study aims to assess the lasting effects of CI on N2O emissions from winter wheat croplands in Southeast China, with traditional irrigation (TI) as the control. CI performed during the rice-growing season had obvious lasting effects on N2O emissions of the subsequent winter wheat-growing season. Compared with TI, CI significantly increased the cumulative N2O emission by 129.1 % during the rice-growing season (p 0.05). The results suggest that CI does not significantly increase the cumulative N2O emission from the rice–winter wheat rotation systems while insuring rice and wheat yields. This study focuses on the lasting effects of water-saving irrigation mode during rice-growing season on N2O emissions during the following wheat-growing season. Thus, it is a development and complement of the previous researches on the effects of water-saving irrigation on N2O emissions from rice–winter wheat rotation croplands.