Water-saving Irrigation Method Research Articles

An Approach to Assessing Farm-Scale Adaptation to Climate Change: The Case Study of Prespa Park

Developing appropriate adaptation practices and coping mechanisms for climate change and evaluating the variables affecting households’ choices are critical for ensuring sustainable agricultural production. In addressing the above issues, this paper presents the results of a multi-method approach at the farm level conducted in the case study of Prespa Park. The data collected by a participatory process were analyzed using descriptive statistics, the 5-point Likert scale, the Delphi method, and a multinomial logit model. The typology of coping and adaptation practices to climate change preferred by households and the reasons for those who failed to adapt are presented. Results revealed that improving technologies for increasing soil health was the most preferred adaptation practice, followed by planting early maturing and drought-tolerant food crop varieties, practicing water-saving irrigation methods or technologies, planting agroforestry systems, and finally perennial agriculture. In terms of coping mechanisms, engaging in off-farm activities was the most used, followed by collecting fuel wood for sale, selling assets like livestock, increasing water storage capacity, and changing farming structure. Small farm holdings, financial constraints, limited off-farm employment opportunities, inadequate infrastructure and technology, and a lack of information about adaptation practices were identified as the main barriers to undertaking adaptation. Performing the multinomial logit analysis, the variables that positively and significantly improve households' ability to adapt to climate change were identified and evaluated. The results of this study should help policymakers and climate change planners come up with better practices for the agricultural sector to adapt to the effects of climate change.

Assessment of modern irrigation versus flood irrigation on groundwater potentiality in old clayey lands

Groundwater management in semiarid and arid regions, like northern Egypt, is essential for the sustainability of scarce resources through monitoring groundwater status and sources of recharge to the aquifer. In the Qalyubia Governorate, Nile Delta, Egypt, the study examined the recharge of groundwater in lands subject to flood irrigation and compared it with water-saving irrigation methods to detect how irrigation practices influence the potentiality of groundwater. A simulation of the two irrigation techniques, flood irrigation, and water-saving irrigation, was performed. Using GMS, simulations are done to calculate the water balance in the main 8 districts of Qalyubia Governorate. In comparison to flood irrigation, it was found that water-saving irrigation has less recharge intensity, which in turn causes a lowering in groundwater levels. The decline in groundwater table ranges between 10 and 50 cm. Modern irrigation influences the potentiality of the Nile Delta aquifer, which can’t be underestimated.

Improving Water Productivity Using Subsurface Drip Irrigation in the Southwest Monsoon Area in Yunnan Province of China

Due to the influence of the Asian southwest monsoon, seasonal drought is serious and water resources are scarce in the Yunnan province of Southwest China. More effective water-saving irrigation methods should be developed to solve the problem of water scarcity in the dry season. In this study, a subsurface drip irrigation method was used to improve the water productivity of tomato cultivation. Deficit irrigation was conducted. We controlled the lower limit of soil moisture at three different levels (55~65%, 65~75%, and 75~85% of the field capacity). The results indicated that the subsurface drip irrigation treatment significantly increased tomato height in the later stage of tomato growth. Due to the buried pipes, the root/shoot ratio was 8~18% higher for subsurface drip irrigation than for surface drip irrigation methods. Though the yields using subsurface drip irrigation methods were slightly lower than those obtained using surface drip irrigation methods, the tomato quality and water productivity improved significantly. The subsurface drip irrigation methods improved the water productivity by 8.5~21.8% at different soil moisture levels and improved the chlorophyll content by 9.1~17.3%. The VC, soluble sugar, soluble solids, and the ratio of sugar to acid increased by 6.5~15.2%, 7.3~21.6%, 4.1~6.6%, and 3.2~20.8%. This study also indicated that by optimizing the irrigation methods and patterns, water productivity and fruit quality could be improved by more than 50%. This research will be helpful for guiding irrigation during the drought season in the southwest monsoon area in Asia.

Prospects of Solar Pump for Irrigation and Household Applications for Climate Resilience in the Coastal Region of Bangladesh

Bangladesh is a climate vulnerable and agricultural country. Coastal region of Bangladesh is severely affected by climate change. To mitigate climate, change a solar pump of flow rate 180 liter per minute was designed and tested in farmers’ fields of Kalapara and Galachipa Upazila (sub-district) of Patuakhali district, Barguna Sadar and Amtali Upazila of Barguna district and Char Fasson and Lalmohon Upazila of Bhola district in the coastal region of Bangladesh for irrigating in high value crops like tomato and brinjal using pond/canal water. One solar pump was installed in each Upazila of off-grid area in 2018 and experiments were conducted during 2018-2021. Each solar pump was operated with 1300 Wp photovoltaic panels and the panels were also used for supplying electricity to home appliances and home water supply when the irrigation time was over. In farmers’ fields, water saving irrigation methods such as drip irrigation and alternate furrow irrigation were conducted. The water savings from drip and alternate furrow irrigation methods over famers’ practice (every furrow irrigation) for tomato were 48.79% and 30.39% and those for brinjal were 47% and 35%, respectively. The benefit cost ratio of the demonstrated solar PV system was found to be 1.62 which was higher than low lift diesel pump (1.30). A small solar pump of 0.8 kW reduced 1.76 ton of carbon emission per year than a similar diesel engine operated pump. The farmers in the project areas are using the solar panels for irrigation, lightings, operating fans, supplying drinking water, sanitation and other purposes. Therefore, solar pump is an environment friendly and climate resilient technology with multiple benefits for small holder farmers in the coastal region of Bangladesh.

Performance of a Drip Irrigation System under the Co-Application of Water, Fertilizer, and Air

The co-application of water, fertilizer, and air is a new water-saving irrigation method based on drip irrigation technology, which can effectively alleviate the phenomenon of soil rhizosphere hypoxia, improve water and fertilizer utilization efficiency, and inhibit the clogging of irrigation equipment in drip irrigation systems. The performance of drip irrigation systems is one of the important factors affecting the effectiveness of the co-application of water, fertilizer, and air. However, the impact of factors such as the aeration method, fertilization device, and working parameters on the performance of drip irrigation systems for the co-application of water, fertilizer, and air is still unclear. Therefore, based on two typical aeration methods, i.e., micro-nano and Venturi aeration, the performance of a drip irrigation system under the co-application of water, fertilizer, and air was studied by comparing and analyzing the effects of different aeration methods, working pressures of the drip irrigation system, and the pressure difference between the inlet and outlet of fertilizer irrigation on the spatial distribution uniformity of water, fertilizer, and air in the drip irrigation pipeline network. The results showed that the pressure difference between the inlet and outlet of fertilization irrigation had no significant impact on system performance, while the working pressure significantly affected system performance. Compared with the effective effect of Venturi aeration on system performance, micro-nano aeration can significantly affect drip irrigation system performance and effectively improve drip irrigation system performance. The micro-nano-aerated drip irrigation system with the co-application of water, fertilizer, and air under a working pressure of 0.1 MPa has better system performance. The research results are of great significance for revealing the mechanism underlying the impact of the co-application of water, fertilizer, and air on the performance of drip irrigation systems and constructing efficient drip irrigation technology for the co-application of water, fertilizer, and air.

What is the applicability of clean production technologies for maize as a countermeasure to reduce on-farm CO2 emissions and increase crop productivity?

Agricultural production activities are the second-largest source of greenhouse gas emissions and one of the most significant sources of carbon emissions. The development of cleaner production in agriculture has become inevitable, focusing on the conservation of the ecological environment quality of the agroecological regions while maintaining sustained, stable, high productivity. Most previous studies failed to examine the quantitative effects of cleaner production methods on agricultural yields and CO2 emissions, focusing instead on the development of standardized technical frameworks and systems for cleaner production. Herein, a meta-analysis was used to evaluate the effects of fertilizer reduction and replacement, integrated straw usage, and water-saving irrigation methods on CO2 emissions and productivity of maize fields. We studied the practical applicability of cleaner production technologies in various regions of China to examine new models of cleaner production for maize cultivation. Our results show that the relationship between the adoption of maize cleaner production technologies and carbon reduction and yield increase is non-linear and influenced by many factors. Fertilizer reduction and substitution technology had the greatest effect on suppressing CO2 emissions from maize fields (−356%), while integrated straw usage technology brought about higher CO2 emissions from fields (434%) due to the return method and soil temperature. The adoption of both integrated straw usage technology (132%) and water-saving irrigation technology significantly increased maize productivity, with water-saving irrigation technology differentiating between the specific environment in which the technology was applied (90% for traditional irrigation and 229% for rainfed planting), and fertilizer reduction and substitution technology having no significant effect on changes in maize productivity. Combined with the practical applicability of cleaner production sub-technologies in maize cultivation, we identified the optimal maize cleaner production model as organic fertilizer substitution technology (proportion <50%) + straw charcoal return technology + sub-film drip irrigation technology (rainfed)/subsurface drip irrigation technology (traditional irrigation).

Response of soil respiration and carbon budget to irrigation quantity/quality and biochar addition in a mulched maize field under drip irrigation.

Biochar addition strongly alters net carbon (C) balance in agroecosystems. However, the effects of biochar addition on net C balance of maize field under various irrigation water quantities and qualities remains unclear. Thus, a field experiment combining two irrigation levels of full (W1) and deficit irrigation (W2 = 1/2 W1), two water salinity levels of fresh (S0, 0.71 g L-1 ) and brackish water (S1, 4 g L-1 ), and two biochar addition rates of 0 t ha-1 (B0) and 60 t ha-1 (B1) was conducted to investigate soil carbon dioxide (CO2 ) emissions, maize C sequestration and C budget. Compared with W1, W2 reduced average cumulative CO2 emissions by 6.5% and 19.9% for 2020 and 2021, respectively. The average cumulative CO2 emissions under W1S1 treatments were 5.4% and 22.3% lower than W1S0 for 2020 and 2021, respectively, whereas W2S0 and W2S1 had similar cumulative CO2 emissions in both years. Biochar addition significantly increased cumulative CO2 emissions by 17.8-23.5% for all water and salt treatments in 2020, and reduced average cumulative CO2 emissions by 11.9% for W1 but enhanced it by 8.0% for W2 in 2021. Except for W2S1, biochar addition effectively increased total maize C sequestration by 6.9-14.8% for the other three treatments through ameliorating water and salt stress over the 2 years. Compared with W1S0, W1S1 did not affect net C sequestration, but W2 treatments significantly decreased it. Biochar addition increased net C sequestration by 39.47-43.65 t C ha-1 for four water and salt treatments for the 2 years. These findings demonstrate that biochar addition is an effective strategy to increase both crop C sequestration and soil C storage under suitable water-saving irrigation methods in arid regions with limited freshwater resources. © 2023 Society of Chemical Industry.

Variation Characteristics and Expression State of Nitrogen and Phosphorus Metering Ratio of Rice in Black Soil under Film Mulching and Irrigation Methods

In order to investigate the effects of film mulching and water-saving methods on soil inorganic nitrogen, nitrogen content of rice organs, nitrogen-phosphorus metering ratio, and nutrient limitation during rice yield formation, two water-saving irrigation methods and black biodegradable film mulching were adopted. The effects of water-saving film mulching on NH4+-N and NO3−-N in 0 to 60 cm soil, nitrogen accumulation and ratio, and nitrogen-phosphorus metering ratio in rice organs were analyzed. The nitrogen-phosphorus-limiting state of rice growth under water-saving film mulching was determined. The results showed that water-saving and film mulching methods could weaken the leaching of NH4+-N and NO3−-N and enhance the nitrogen uptake of rice. The water-saving method of mulching could reduce the metering ratio of nitrogen and phosphorus in rice organs. The panicle maturity process had been in a state of nitrogen limitation, and the effect was gradually enhanced. The nitrogen and phosphorus metering ratio of panicles was positively correlated with NH4+-N accumulation in the 0 to 60 cm soil layer and nitrogen accumulation of rice organs, and negatively correlated with soil NO3−-N accumulation under film mulching and water-saving methods. The correlation between stems and leaves’ nitrogen and phosphorus metering ratios and influencing factors was basically opposite to that of panicles’ nitrogen and phosphorus metering ratio. This study can provide a reference for the formulation of a fertilization system under film mulching in the black soil region of northeast China.

Italian winegrowers’ and wine makers’ attitudes toward climate hazards and their strategy of adaptation to the change

This study reports the results of a survey disseminated to Italian winegrowers and wine makers to understand their attitude toward the main climate risk factors on grape and wine productions and their willingness to proactively act in facing the related consequences. A general noticeable concern about the future effects of climate change and variability emerged, even with some differences between stakeholders operating in different geographic and climatic areas. Current signals of adaptation mostly emerged at technological level, but they also included the varietal choice, with evidence to a switch from traditional varieties to others showing better pest and drought tolerance. In addition, some climate-smart cultural practices are considered ranging from water-saving irrigation methods to sustainable energy management.

Water Management for Sustainable Irrigation in Rice (Oryza sativa L.) Production: A Review

In the face of the negative impacts of climate change and the accelerated growth of the global population, precision irrigation is important to conserve water resources, improve rice productivity and promote overall efficient rice cultivation, as rice is a rather water-intensive crop than other crops. For several decades, various water conserving technologies have been studied in order to significantly increase water use efficiency (WUE). The objective of this paper is to review the main technologies and approaches for assessing the water requirements of rice crop in order to contribute to water saving in irrigated rice production, after clarifying the performance indicators of the irrigated systems. Several scientific articles from previous studies were consulted and analyzed. These studies showed that irrigation water conservation includes a wide range of practices, staring from the crop irrigation water requirements assessment to the implementation of the water saving practices on the field. In addition, irrigation water conservation technologies could be categorized into three groups, namely water-conserving irrigation systems, water-saving irrigation methods, and water-conserving agronomic practices. The influence of the individual and combined irrigation water use efficiency tools was highlighted. This paper will enable researchers to acquire knowledge on water-saving methods for estimating the rice crop water requirements and thus allow them to effectively contribute to improve the performance of irrigated rice cultivation systems using various water conservation technologies.

Effects of Irrigation Regimes and Rice Varieties on Methane Emissions and Yield of Dry Season Rice in Bangladesh

Adoption of the right rice variety and water-saving irrigation method could reduce greenhouse gas (GHG) emissions in lowland rice cultivation. A study was conducted at the research farm of Bangladesh Agricultural University, Mymensingh, Bangladesh, in 2019 during the Boro (dry) season to determine the impacts of different rice varieties (BRRI dhan29, BRRI dhan47, BRRI dhan69, Binadhan-8, Binadhan-10, and Binadhan-17) on methane (CH4) emissions under two irrigation methods, i.e., alternate wetting and drying (AWD) and continuous flooding (CF). The treatments were laid out in a split-plot design, considering water regime as the main plots and rice variety as the sub-plots. The emission rates of CH4 were determined by collecting air samples using the closed chamber technique and measuring the concentrations using a gas chromatograph. CH4 emission rates varied with the growth and development of the rice varieties. The lowest cumulative CH4 emission rate was observed in Binadhan-17, particularly under AWD irrigation. Across the rice varieties, AWD irrigation significantly reduced the cumulative CH4 emissions by about 35% compared with CF. No significant variation in rice yield was observed between AWD (5.38 t ha−1) and CF (5.16 t ha−1). This study suggests that the cultivation of Binadhan-17 under AWD irrigation could be effective at reducing the carbon footprint of lowland rice fields.

ANALISIS PENGARUH METODE SRI DAN KONVENSIONAL TERHADAP LUAS LAYANAN IRIGASI PADA BENDUNGAN MENINTING

The biggest water demand is in the agricultural sector. This great need is caused by the irrigation system with continuous inundation (conventional). One of the water-saving irrigation methods is the System of Rice Intensification (SRI) method. The SRI method of giving water is done intermittently. One of the obstacles to the application of the SRI method is a continuous water source. The dam is one of the water sources whose water availability is relatively easy to manage, making it suitable for irrigation applications using the SRI method. This study aims to analyze the provision of irrigation water for SRI and conventional systems at the Meninting Dam and its effect on the area of irrigation services. In this study, an analysis of water availability was carried out using awlr data, an analysis of irrigation water requirements using the conventional method and the SRI method. Reservoir simulation analysis is used to determine the area that can be irrigated, planting intensity and reservoir reliability. The results for the conventional method of irrigated area that can be served are 1,559 ha with a planting intensity of 300% and a reservoir reliability of 95.83%. At the same intensity and reliability as the conventional method, the SRI method can irrigate 1,980 ha of irrigation area, so using the SRI method can increase the service area by 421 ha or can increase the service area by 27%.

Optimized border irrigation delays winter wheat flag leaf senescence and promotes grain filling.

Border irrigation is still the main irrigation method in the Huang-Huai-Hai Plain of China (HPC), and the suitable irrigation border length for water saving and high yield under traditional irrigation is still unclear. Therefore, a 2-year traditional border irrigation experiment (2017-2019) was conducted on the HPC. Four border lengths were tested: 20m (L20), 30m (L30), 40m (L40), and 50m (L50). These treatments were given supplementary irrigation at jointing and anthesis. An exclusively rainfed condition formed the control treatment. Compared with other treatments, the activities of superoxide dismutase antioxidant and sucrose phosphate synthetase, and the contents of sucrose and soluble proteins after anthesis were higher in the L40 and L50 treatments, while the content of malondialdehyde content was lower. Therefore, the L40 treatment effectively delayed the decrease in the soil plant analysis development (SPAD) value and chlorophyll fluorescence characteristics, promoted grain filling, and achieved the highest thousand-grain weight. Compared with the L40 treatment, the grain yields of the L20 and L30 treatment were significantly reduced, while the water productivity of the L50 treatment was significantly reduced. These findings suggest that 40m was the optimal border length for both high yield and water saving in this experiment. This study provides a simple and low-cost water-saving irrigation method for winter wheat in the HPC under traditional irrigation, which can help alleviate the pressure of agricultural water use.

Подходы к снижению негативных последствий использования слабо- и маломинерализованных вод в орошаемом земледелии

Purpose: to identify the most suitable measures aimed at achieving the rational use of brackish and low-mineralized water resources for the Republic of Crimea, based on an analysis of foreign and domestic experience in ensuring the environmental safety of irrigation with limitedly suitable waters. Discussion: during the study, a review of foreign and domestic developments to reduce (prevent) the negative impact of irrigation with limitedly suitable water resources on soil and crops and an analysis of approaches, implemented in the Crimean region, aimed at ensuring environmental safety of using brackish and low-mineralized waters in irrigated agriculture was carried out. It has been found that the main technological solutions aimed at reducing the negative impact of using limitedly suitable water in agriculture include: determining the maximum permissible mineralization of irrigation water from an ecological and economic point of view, reducing irrigation rates, selecting effective agronomic practices, justification the irrigation method and preliminary water treatment, carrying out washing with fresh water, forecasting and modeling of the water-salt regime. The first four approaches are mainly used in the Republic of Crimea. In general, their use makes it possible to prevent a significant decrease in crop yields and the intensive development of soil degradation processes. Conclusions: to ensure the environmental safety of irrigation with limitedly suitable waters, approaches that include the use of water resources with mineralization up to 3 g/l in combination with water-saving irrigation methods, reduction of irrigation rates and the application of chemical ameliorants, it is advisable to supplement with annual water quality and soil condition monitoring, as well as to provide for forecasting the salt regime of the fertile layer in the future.

Drip irrigation improves spring wheat water productivity by reducing leaf area while increasing yield

To mitigate the climate change-induced water shortage and realize the sustainable development of agriculture, drip irrigation, a more efficient water-saving irrigation method, has been intensively implemented in most arid agricultural regions in the world. However, compared to traditional border irrigation, how drip irrigation affects the biophysical conditions in the cropland and how crops physiologically respond to changes in biophysical conditions in terms of water, heat and carbon exchange remain largely unknown. In view of the above situation, to reveal the mechanism of drip irrigation in improving spring wheat water productivity, paired field experiments based on drip irrigation and border irrigation were conducted to extensively monitor water and heat fluxes at a typical spring wheat field (Triticum aestivum L.) in Northwest China during 2017–2020. The results showed that drip irrigation improved yield by 10.3 % and crop water productivity (i.e., yield-to-evapotranspiration-ratio) by 15.6 %, but reduced LAI by 16.9 % in contrast with border irrigation. Under drip irrigation, the lateral development of spring wheat roots was promoted by higher soil temperature combined with frequent dry-wet alternation in the shallow soil layer (0–20 cm), which was the basis for efficient absorption of water and fertilizer, as well as efficient formation of photosynthate. Meanwhile, drip irrigation increased net radiation and decreased latent heat flux by inhibiting leaf growth, thereby increased sensible heat, causing a higher soil temperature (+1.10 ℃) and canopy temperature (+1.11 ℃). Further analysis proved that soil temperature was the key factor affecting yield formation. Based on the above conditions, the decrease in leaf distribution coefficient (−0.030) led to the decrease in evapotranspiration (−5.7 %) and the increase in ear distribution coefficient (+0.029). Therefore, drip irrigation emphasized the role of soil moisture in the soil-plant-atmosphere continuum, enhanced crop activity by increasing field temperature, especially soil temperature, and finally improved yield and water productivity via carbon reallocation. The study revealed the mechanism of drip irrigation for improving spring wheat yield, and would contribute to improving Earth system models in representing agricultural cropland ecosystems with drip irrigation and predicting the subsequent biophysical and biogeochemical feedbacks to climate change.

Subsurface irrigation with ceramic emitters: Optimal working water head improves yield, fruit quality and water productivity of greenhouse tomato

Greenhouses are widely used in Northwest China, especially for tomato, which is the dominant crop. Subsurface irrigation with ceramic emitters (SICE) is a new water-saving technology for continuous low-rate water supply at constant soil moisture. However, a lack of knowledge still existed to define the suitable working water head for SICE to decrease water loss and promote tomato production, fruit quality, and water productivity. In this study, a greenhouse experiment was conducted during spring and autumn cultivation periods under SICE for five working water heads of 0.1 m to 0.5 m with intervals of 0.1 m and subsurface drip irrigation (SDI). The verified HYDRUS-2D model evaluated water balance components and water productivity. A structural equation model (SEM) was developed to determine interactive impacts of SICE and meteorological conditions in greenhouse on tomato yield, fruit quality, and water productivity. The results showed that SICE with a working water head of 0.4 m could be recommended, which created a suitable soil water content of the root zone within 70%–80% of field capacity (FC), resulting in a reduction of water loss from actual evaporation (Ea) and deep percolation (DP) by 12.32% and 21.88% respectively relative to SDI. Fruit weight, yield, water use efficiency (WUE), and irrigation water use efficiency (IWUE) were increased by 8.96%, 8.03%, 19.44%, and 16.05% respectively compared to SDI. Moreover, soluble sugar, organic acid, lycopene, vitamin C, and sugar acid ratio were enhanced by 2.41%, 12.19%, 14.40%, and 2.67% under SICE with the suggested working water head respectively compared with SDI. We recommended that supplemental lighting combined with SICE in autumn cultivation was necessary to ensure tomato production and fruit quality. This study provides an alternative water-saving irrigation method for greenhouse growers to maintain tomato yield and fruit quality in Northwest China.

Effect of Aeration on Blockage Regularity and Microbial Diversity of Blockage Substance in Drip Irrigation Emitter

Aerated drip irrigation is rendered as a new water-saving irrigation method based on drip irrigation technology, which is endowed with the function of effectively alleviating the problem of rhizosphere hypoxia in crop soil, enhancing the utilization rate of water and fertilizer; as a result, it improves the harvest and quality of crops. However, clogged emitters are important indexes, among others, that pose an influence to the service effect and life duration of drip irrigation systems. At present, the working principle and mechanism of the influence of air feeding on the blockage of drip irrigation emitters remain unclear. Therefore, based on the two gas filling methods of the micro/nano bubble generator and Venturi injector, the dynamic change process for the average flow ratio of an air-filled drip irrigation emitter was studied by the method of emitter plugging test. 16S rRNA sequencing was used to analyze the microbial diversity of the emitter plugs. The results show that the air injection can pose influence on the clogging procedure of drip irrigation emitters, and more importantly, it makes the distribution of blocked emitters more uniform, thus improving the uniformity of the system. Different filling methods have different effects on the blockage of the emitter. Among them, the blockage time of drip irrigation system under the micro/nano aerated drip irrigation (MAI) mode is 5.73 times longer than that under unaerated drip irrigation (UVI), and similarly, Venturi gas drip irrigation (VAI) is close to that under UVI. The filling method changed the microbial diversity of the blockage in the emitter. Among them, the number of operational taxonomic unit (OTU) unique to MAI was 2.1 times that of UVI, and the number of OTU unique to VAI was 1.3 times that of UVI. Meanwhile, gas addition will inhibit the growth of Nitrospirae and Proteobacteria microbial communities and promote the growth of Firmicutes and Actinobacteria microbial communities. Furthermore, the increase in microbial extracellular polymer in the plugging material of the emitter was inhibited and the plugging process of the emitter was slowed down. The research results are of great significance in the disclosure of the clogging mechanism of drip irrigation emitter and constructing the green, anti-blockage technology of aerated drip irrigation.

Improving Leaf Photosynthetic Performance of Apple through a Novel Root-Zone Irrigation in the Loess Plateau

As freshwater becomes an increasingly scarce and expensive natural resource, novel water-saving irrigation methods for dwarfing apple orchards are needed in the Loess Plateau. However, studies are lacking on the effects of novel root-zone irrigation technology on leaf-level photosynthesis, which directly determines the yield and survival ability of trees. In this study, the leaf gas characteristics and water status of five-year-old dwarfing apple trees in the Loess Plateau of China were monitored during the 2016–2017 growing seasons under water storage pit irrigation (WSPI) and surface irrigation (SI) treatments. Under WSPI, the leaf water potential (Ψm), net photosynthesis rate (Pn), stomatal conductance (gs), and chlorophyll content (Chl) were significantly higher than those under SI (by 12.21–28.36%), while non-photochemical quenching, superoxide dismutase, and sucrose were lower. Compared with SI, WSPI improved dwarfing apple yield by 25.4% and 26.7% in 2016 and 2017, respectively. WSPI increased the photosystem II (PSII) activity by increasing the chlorophyll fluorescence features (the potential quantum yield of PSII (Fv/Fm), actual quantum yield (ΦII), photochemical quenching (qP), and electron transport rate (ETR)). Principal component analysis showed that Ψm, Chl, the chlorophyll fluorescence features (qP, ΦII, and ETR), Pn, and gs could represent the leaf photosynthetic difference between WSPI and SI treatments. Results indicated that apple under WSPI could improve its yield through enhancing leaf photosynthetic performance, and water storage pit irrigation is an effective root-zone irrigation method for apple orchards on the Loess Plateau.

Optimizing Deficit Irrigation Management to Improve Water Productivity of Greenhouse Tomato under Plastic Film Mulching Using the RZ-SHAW Model

Deficit irrigation (DI) is a widely recognized water-saving irrigation method, but it is difficult to precisely quantify optimum DI levels in tomato production. In this study, the Root Zone Water Quality-Simultaneous Heat and Water (RZ-SHAW) model was used to evaluate the potential effects of different DI levels on tomato growth in a drip-irrigated field. Combinations of five DI scenarios were tested in greenhouse field experiments under plastic film mulching according to the percentage of crop evapotranspiration (ET), i.e., ET50, ET75, ET100, ET125, and ET150. The model was calibrated by using the ET100 scenario, and validated with four other scenarios. The simulation results showed that the predictions of tomato growth parameters and soil water were in good agreement with the observed data. The relative root mean square error (RRMSE), the percent bias (PBIAS), index of agreement (IoA) and coefficient of determination (R2) for leaf area index (LAI), plant height and soil volumetric water content (VWC) along the soil layers were &lt;23.5%, within ±16.7%, &gt;0.72 and &gt;0.56, respectively. The relative errors (REs) of simulated biomass and yield were 3.5–8.7% and 7.0–14.0%, respectively. There was a positive correlation between plant water stress factor (PWSF) and DI levels (p &lt; 0.01). The calibrated model was subsequently run with 45 different DI scenarios from ET0 to ET225 to explore optimal DI management for maximizing water productivity (WP) and yield. It was found that the maximum WP and yield occurred in ET95 and ET200, with values of 28.3 kg/(ha·mm) and 7304 kg/ha, respectively. The RZ-SHAW demonstrated its capacity to evaluate the effects of DI management on tomato growth under plastic film mulching. The parameterized model can be used to optimize DI management for improving WP and yield based on the water stress-based method.

Effect of Water Saving Irrigation Method on Physical-Chemical Characteristics of Local Rice

Water-saving irrigation solves the water problem in rice cultivation. Where, the problem of drought due to climatic factors and competition in the use of air between sectors makes the main air requirement for rice plants. The quality of the grain affects the quality of rice as the raw material, while the cultivation technique, climate, and biotic and abiotic inspections affect the quality of the grain. This study aims to determine the physical-chemical characteristics of rice with water-saving irrigation applications. The study used 5 treatments of water availability in the field, namely less than 50% of available water, 50%-60% of available water, 60% -70% of available water, 70% -80% of available water, saturated and ach treatment three replications. Physical properties observed are head rice, broken rice, and groats. Chemical properties analyzed were amylose content, moisture content, ash content, fat content and protein content. Based on the analysis, it is known that the availability of water in the land during the plant growth period affects the chemical properties of the rice of the Bujang Marantau variety and based on the specifications for the quality requirements of rice (SNI 6128: 2015) it is included in the medium quality class 1.