Reduce Irrigation Water Research Articles

‘They adopt, I also adopt’: The neighborhood effects and irrigator farmers’ conversion to adopt water-saving irrigation technology

Promoting water-saving irrigation technology (WSIT) has long been recognized as an effective measure to reduce irrigation water use and alleviate regional water poverty. Neighbours are the groups with the most interaction, the most intensive contact and the most frequent communication in agricultural production. In this paper, based on a field survey of irrigator farmers of China, experiments were conducted to evaluate the contribution of neighbour effect to farmers’ WSIT behaviour and its moderating mechanism between neighbour effect and technology adoption. The results show 26.7 % farmers adopt water-saving technology and these farmers often have strong neighborly relationships. In particular, neighbor effect significantly promote WSIT adoption by 42.1 % and farmers with strong neighborly effects apply significant higher technology compared to farmers with weak neighbourly effects. Furthermore, mechanism results indicated that neighbour effects indirectly influence farmers' adoption of water-saving irrigation technology through three pathways: reducing information search costs, mitigating agricultural production risks and benefiting from the demonstration effect. Moreover, the heterogeneous results report that higher-income, lower digital and lower training frequency farmers will benefit more from the NE in terms of WSIT. Overall, this research provides a micro foundation and policy implications for the promotion of WSIT, and sheds light upon how the government can formulate relevant policies to promote the sustainable development of agricultural water resources.

Variability of seasonal temperature from 1990 to 2020 within Oum Er Rbia hydraulic basin (Morocco): Study of trends and anomalies

Abstract The fifth report of the Intergovernmental Panel on Climate Change (IPCC) indicates that global temperatures have increased during the 20th century. In Morocco, numerous studies have unveiled that the nation has been contending with the effects of global warming for several decades, attributed to its geographical location. The studies have mainly focused on the evolution of rainfall and the recurrence of droughts. Nevertheless, temperature variations remain less addressed, especially at large spatial scales. This paper aims to study the seasonal temperature variability in the large hydraulic basin of Oum Er Rbia, focusing on its anomalies and trends as well as identifying their impacts on the basin’s territory. Indeed, the large basin of Oum Er Rbia occupies more than 48,.000 km2 and is characterized by an arid to semi-arid climate. Its water resources are important and play an essential role in the country’s socio-economic development. This basin is well-known for its agricultural activity. Although its water and economic potential are significant, the great basin is considered vulnerable to climatic variations, which strongly condition its development. Considering the significance of temperature trends within the framework of global warming, this current study delves into the topic of seasonal temperature variability within the expansive hydraulic basin of Oum Er Rbia. Based on statistical analysis using the temperature anomaly index and the Mann-Kendall trend test, this study reveals that strong interannual variability marked the evolution of seasonal temperatures during the period of 1990-2020, with a remarkable upward trend during the autumn and spring. When the temperature increase, the temperature increases in turn: thus, the negative impacts affect both water resources and the agriculture sector, which suffers from the combined effect of increased evapotranspiration and reduction of irrigation water.

Potential of ecological water treatment elements to reduce pollution of river water used for urban agriculture in Addis Ababa, Ethiopia

Cities in developing countries, such as Addis Ababa, face enormous challenges as a result of high demand for food and clean water, as well as the generation of large amounts of urban waste that is discharged into natural water bodies, contaminating rivers, lakes, and other freshwater bodies used in urban agriculture. Farmers in Addis Ababa and nearby areas use polluted irrigation water diverted from the highly contaminated Little and Great Akaki rivers. The study aimed to assess how well a floating treatment wetland with vetiver grass could reduce irrigation water pollution at the Mekanisa-Gofa-Lafto Cooperative (MGLC) farm in Addis Ababa, Ethiopia. Additionally, the study sought to provide design recommendations that could be implemented at the farmer level. The irrigation water underwent a 7-day treatment using a Vetiver grass floating treatment wetland. A field test was also conducted to evaluate the effectiveness of the floating treatment wetland in reducing pollutants at the study site. The results showed that the floating treatment wetland was able to reduce the Biochemical Oxygen Demand (BOD) (73.68%), Chemical Oxygen Demand (COD) (73.92%), Acidity/Basicity (pH) (0.39%), Chloride (Cl−) (43.12%), Total Hardness (66.56%) and Total Suspended Solid (TSS) (96.21%) values, approaching the recommended irrigation water quality guideline values within 3 days. In contrast, there was an increase in Electro Conductivity (EC) (22.2%) and Sodium (Na) (15.2%) concentrations, which exceeded the recommended values, due to evapotranspiration or the entry of the surrounding soil into the irrigation water of the study site.

Crop water productivity assessment and planting structure optimization in typical arid irrigation district using dynamic Bayesian network

Enhancing crop water productivity is crucial for regional water resource management and agricultural sustainability, particularly in arid regions. However, evaluating the spatial heterogeneity and temporal dynamics of crop water productivity in face of data limitations poses a challenge. In this study, we propose a framework that integrates remote sensing data, time series generative adversarial network (TimeGAN), dynamic Bayesian network (DBN), and optimization model to assess crop water productivity and optimize crop planting structure under limited water resources allocation in the Qira oasis. The results demonstrate that the combination of TimeGAN and DBN better improves the accuracy of the model for the dynamic prediction, particularly for short-term predictions with 4 years as the optimal timescale (R2 > 0.8). Based on the spatial distribution of crop suitability analysis, wheat and corn are most suitable for cultivation in the central and eastern parts of Qira oasis while cotton is unsuitable for planting in the western region. The walnuts and Chinese dates are mainly unsuitable in the southeastern part of the oasis. Maximizing crop water productivity while ensuring food security has led to increased acreage for cotton, Chinese dates and walnuts. Under the combined action of the five optimization objectives, the average increase of crop water productivity is 14.97%, and the average increase of ecological benefit is 3.61%, which is much higher than the growth rate of irrigation water consumption of cultivated land. It will produce a planting structure that relatively reduced irrigation water requirement of cultivated land and improved crop water productivity. This proposed framework can serve as an effective reference tool for decision-makers when determining future cropping plans.

Effect of deficit irrigation and partial rootzone drying on the water consumptive use, growth and yield of faba bean (vicia faba L.) in a gypsiferous soil

Iraq’s farming sector is under increasing pressure to improve water use productivity as a result of the recent drought, environmental concerns regarding sustainable river ecosystems, and government policies on water metering and allocations. To cope with scarce supplies, deficit irrigation, and partial rootzone drying, defined as the application of water below full crop-water requirements, is an important tool to achieve the goal of reducing irrigation water use. It is necessary to develop new irrigation scheduling approaches, not necessarily based on full crop water requirement, but ones designed to ensure the optimal use of allocated water. These two methods of irrigation are one way of maximizing water use efficiency (WUE) for higher yields per unit of irrigation water applied: the crop is exposed to a certain level of water stress either during a particular period or throughout the whole growing season. The expectation is that any yield reduction will be insignificant compared with the benefits gained through diverting the saved water to irrigate other crops. This paper reviews the yield response of the faba bean (Vicia faba L.). The deficit of irrigation on gypsiferous soils is not known. A field experiment was carried out to study the effect of deficit irrigation and partial drying of the root system on the growth and yield of the bean Randomized Complete Blocks (RCBD) design in gypsiferous soil in the fields of the College of Agriculture- Tikrit University, which is located on Latitude 49° 40ʹ 34˝ North and Longitude 40° 38ʹ 43˝ East At an altitude of 129 m above sea level. The study included seven treatments of full irrigation, deficit irrigation, 25, 50 %, and fixed, alternating partial drying. The seeds of the Barcelona variety were sown for the season on 16/10/2021 and harvested on 2/4/2022. The results showed that the full irrigation treatment gave the highest water consumption use of 635 mm, while the alternative partial root drying decreasing 50% gave the lowest water consumption use of 245 mm and gave the highest crop water use efficiency of 2.0 kg m-3. Treatment full irrigation gave the highest seed yield of 5186.3 kg.ha-1, While the 50% deficit irrigation treatment gave the highest dry weight of the root system, which was 25.6 gm.plant-1.

Alternate wetting and drying: a water-saving technology for sustainable rice production in Burkina Faso?

With emerging water scarcity and rising fertilizer prices, optimising future water use while maintaining yield and nutrient efficiency in irrigated rice is crucial. Alternate wetting and moderate soil drying irrigation (i.e., re-irrigation when the water level reaches 15 cm below the soil surface) has proven to be an efficient water-saving technology in semi-arid zones of West Africa, reducing water inputs without yield penalty. Alternate wetting and severe soil drying (AWD30), by re-irrigating fields only when the water table reaches 30 cm below the soil surface, may further reduce water inputs compared to farmers’ irrigation practices (FP). However, acute soil drying may impair fertilizer use efficiency and reduce the bio-availability of some key nutrients. This study assessed the potentials and risks associated with AWD30 for smallholder rice farmers in the semi-arid zones of West Africa. We conducted 30 on-farm field trials over three seasons (wet and dry seasons of 2019, and dry season of 2020), in Kou Valley, Burkina Faso. We assessed yield, water productivity, nutrient uptake, and use efficiency under AWD30 and FP. In FP, farmers maintained their fields submerged as frequently as possible according to the scheme-dependent water provision schedule. With AWD30, irrigation frequency was reduced by 30%, however, soils were seldom completely dried due to a shallow groundwater table. Compared to FP, AWD30 reduced irrigation water input by 37% with no significant effects on grain yields (average of 4.5 Mg ha−1), thus increasing average water productivity by 39%. Both irrigation management practices provided comparable crop uptake of N, P, and K, and use efficiencies of applied N and P. However, the N content in straw and the P concentration in grain generally increased with total water input (rain + irrigation). We conclude that at locations with a shallow groundwater table, AWD30 can effectively save irrigation water without significantly reducing the grain yield and the use efficiency of applied mineral nutrients.

Light extinction coefficient and radiation use efficiency of two greenhouse basil (ocimum basilicum L.) cultivars under deficit irrigation

ABSTRACT This two-year experiment with different planting seasons (April 2018 and August 2021) aimed to determine the effect of deficit irrigation (DI) levels (DI0: 100%, DI30: 70%, and DI60: 40% field capacity) on light interception, light extinction coefficient (k), dry biomass and radiation use efficiency (RUE) of two basil cultivars (Green and Purple). The greenhouse experiment was arranged in a split-plot design with three replications. The results showed that the k values ranged from 0.57 to 0.68 and 0.31 to 0.43 in April and August planting, respectively. The cumulative solar radiation interception, dry biomass, and RUE depended on DI levels, harvest numbers, and seasons. In two study years, dry biomass decreased and RUE increased with the reduction in irrigation water at all harvests and their total. Compared to DI0, basil dry biomass did not show a considerable decrease under DI30 in three harvests in April planting and in the first and second harvests in August planting. April planting had the higher cumulative solar radiation interception in the first and third harvest than the August planting. The basil dry biomass and RUE in the April planting were higher than those in the August planting at all three harvests and their total.

A Multicriteria Decision Analysis Model for Optimal Land Uses: Guiding Farmers under the New European Union’s Common Agricultural Policy (2023–2027)

Focusing on sustainability, the new Common Agricultural Policy (2023–2027) sets ambitious goals for water management, as reducing irrigation water use is a vital issue. Cooperation among farmers, relevant authorities, and researchers plays a significant role in achieving these objectives. Therefore, this study applies a multicriteria mathematical programming model to optimize land use, considering water use, profit, labor, and cost. The model was applied to three farmer groups located in Greece and proved to be valuable in the implementation of irrigation water use. Using the same methodology, two additional cases of farmer groups that utilize drylands are presented in complementary ways to investigate how the new CAP affects non-irrigated land uses. Regarding the irrigated case, reducing water usage involves decreasing the land dedicated to crops characterized by high water demand, such as rice, corn, vetch, and clover. This adjustment stems from the necessity to replace irrigated land with non-irrigated land because climate change demands low water consumption for crops and underscores the importance of the new policy framework to promote sustainable agriculture. As for the non-irrigated case, achieving optimal farm planning entails reducing the cultivated areas of vetch, grassland, and sunflower. This result is driven by the need to increase crops receiving primary subsidies, highlighting the necessity for non-irrigated farms to enhance their profitability through the benefits provided by the Common Agricultural Policy. Lastly, it is important to note that this study significantly contributes to guiding decision-makers in achieving alternative agricultural land uses and farm plans while also aiding in the comprehension of the new cross-compliance rules.

Improve food, water, and economic benefits in China’s oases through crop switching

China’s oases are the center of human life and economic development for tens of millions of inhabitants in drylands. However, oases have experienced a significant expansion of cropland during the past three decades, which has resulted in rapidly increasing agricultural water demand and increasing water shortages in the region. Although crop switching is recognized as a promising strategy for improving the sustainability of agricultural production, little is known about how much it can improve the sustainability of oasis cropping systems and whether there are trade-offs among multiple sustainability goals. Here, we used a crop-water-use model, data on crop production and nutrient content, observational data on streamflow, and oasis land-use data to assess the impacts of different crop switching scenarios on water demand, nutrient supply, and income. The results showed that oasis agricultural water demand increased from 28.5 km3 to 41.1 km3 between 1987 and 2017, with 74.6 % of the oasis counties experiencing increasing agricultural water stress. By replacing all crops with those having the lowest water demand in each respective county, the demand for irrigation can be reduced by 23.1 %, and the demand for groundwater reduced by as much as 72.8 %. Crop switching scenarios that also consider crop species diversity, in which replacing the highest water demand crops with alternative crops (those with the lowest water demands, highest protein production, or highest calorie production) in each county can effectively reduce irrigation water demand (8.5–12.9 % for streamflow and 32.7–43.3 % for groundwater), while increasing protein (21.3–35.8 %) and calorie (27.5–42.7 %) production as well as income (1.4–2.4 %). Our research provides potential solutions to effectively alleviate the conflict between agricultural development and the environment in oasis regions.

Assessing the levels of soil water availability that minimize the damage of heatwaves to potted grapevines

The adverse effects of heatwaves on viticulture could be, at least partly, mitigated by generous soil water availability. As climate change will also likely reduce irrigation water, knowing to which extent soil water availability could be decreased under the heatwaves without compromising plant performances would be important. In this pot experiment, we differentiated soil water availability by compensating 100% (T100), 70% (T70), 40% (T40) and 10% (T10) of vine transpiration. Grapevines (cv. Sauvignon) were then subjected to a 11-day heatwave (Tmax 40 °C) and to a post-heat stress recovery phase. Soil water potential between -0.05 to -0.2 MPa, respectively, in T100 and T70 enabled the plants to maintain high net CO2 assimilation (Pn), stomatal conductance (gs), and leaf transpiration (Eleaf) which kept the leaf temperature (Tleaf) below the ambient temperature and promoted the plant growth. During the heatwave, T100 and T70 vines decreased their photochemical yield and dissipated the excess energy via regulated non-photochemical heat dissipation, and resumed their photochemical activities upon removing the heat stress. Further reduction in soil water potential to -0.4 and and -1.2 MPa in T40 and T10, respectively, decreased Pn and gs and restrained Eleaf, causing a significant increase in Tleaf during the heatwave, and limited the plant recovery after the heat stress. Nonetheless, the maximum efficiency of PSII (Fv/Fm) showed quite high resistance to heat stress in all treatments. These findings suggest that decreasing soil water availability to reach soil water potential levels close to -0.2 MPa implies higher efficiency in using water resources during a heat wave without limiting plant growth.

Effects of alternate wetting and drying irrigation on yield, water-saving, and emission reduction in rice fields: A global meta-analysis

With limited natural resources and uncertain climate, increasing food production must mitigate the environmental impacts. Rice, a water-intensive grain crop, contributes significantly to greenhouse gas (GHG) emissions in agricultural systems. Alternate Wetting and Drying (AWD) Irrigation stands out as the prevailing water-saving irrigation technique in rice fields worldwide. Nonetheless, the effects of AWD on yield variation, water conservation, and emissions reduction as well as the synergies and trade-offs between the effects remain unclear. Here a global meta-analysis of 437 literature sources covering 93 % of global rice production was conducted to quantify changes in yield, water utilization, and GHG emissions following AWD implementation. Results show that, on a global scale, AWD reduces irrigation water usage by 33.88 % and enhances water use efficiency, irrigation water use efficiency, and water productivity by 20.27 %, 47.58 %, and 29.63 %, respectively. However, there is a minor decrease in yield by 1.56 %. Notably, AWD leads to a noteworthy 47.47 % reduction in methane emissions, counterbalanced by a 52.20 % rise in N2O emissions, ultimately resulting in a decrease in global warming potential (GWP) and greenhouse gas intensity (GHGI) by 39.38 % and 38.06 %, respectively. The AWD threshold is the most significant predictive factor, adopting a suitable threshold can greatly improve the accuracy of AWD implementation. Soil properties also play a pivotal role, with pH levels > 7 or soil organic carbon (SOC) < 12 g/kg correlating to more pronounced yield losses. Implementing reasonable field management measures, such as suitable rice varieties and straw incorporation can effectively increase rice productivity. Approximately 60.36 % of the data falls within the “win–win” zone, demonstrating simultaneous in yield increases, water conservation, and emissions reduction. AWD is more suitable for acidic soils with high SOC (>12 g/kg) and a light texture. This study introduces novel insights for analyzing the synergies and trade-offs within the food–water–climate nexus.

Effects of intercropping and regulated deficit irrigation on the yield, water and land resource utilization, and economic benefits of forage maize in arid region of Northwest China

Intercropping has been widely recognized to have great advantages in terms of increasing yield, controlling pests and diseases, and saving land, particularly in developing countries. Regulated deficit irrigation reduces water consumption and improves water productivity (WP). However, it is unclear whether the combination of intercropping and deficit irrigation could improve crop yield and WP simultaneously. In this experiment, three planting modes, including forage maize (Zea mays L.) monoculture (M), lablab bean (Lablab purpureus L.) monoculture (L), and maize-lablab bean intercropping (ML) were used. Six irrigation modes were set for each planting mode, including severe water deficit (W1), late water deficit (W2), alternate water deficit (W3), late moderate water deficit (W4), early moderate water deficit (W5), and full irrigation (W6). Results showed that compared with M, the ML treatment significantly increased the fresh forage yield (9.8%–17.0%), hay yield (9.5%–13.1%), crude protein yield (22.9%–25.9%), and WP (7.8%–8.7%). The W5 treatment achieved similar fresh forage yield, hay yield, and crude protein yield as that of the W6 treatment but reduced irrigation water by 25% and increased the WP (21.9%–24.8%). Intercropping achieved a high-water equivalence ratio (WER;1.52–1.81) and land equivalence ratio (LER;1.56–1.84), indicating its advantages over monocultures. The W6 treatment had the lowest WER and LER, suggesting that excessive irrigation can reduce the efficiency of utilizing land and water resource in maze-based forage production. Among all treatments, ML–W5 achieved the highest net income and output to input ratio. Overall, intercropping of forage maize and lablab bean with moderate deficit irrigation at an early stage could be used as a high-yield and efficient forage production system in the arid areas of northwest China.

Water Use Efficiency in a Deficit-Irrigated Orange Orchard

Citrus is a subtropical fruit tree with high water requirements. This study aimed to determine the effects of water deficit on an orange orchard subjected to different water-saving strategies. The study was realised in an orange orchard in a semiarid area by adopting four different water management techniques: 100% crop evapotranspiration (control); SSDI—subsurface sustained deficit irrigation; RDI—regulated deficit irrigation; PRD—partial rootzone drying treatment during five growing seasons. The experimental design foresaw a randomised block design with six replicates per treatment (24 index plants). The results of the study showed that the water-saving strategies reduced irrigation water consumption by 25% (SSDI), 33% (RDI), and 49% (PRD) compared to the fully irrigated treatment without yield reduction, thus increasing water use efficiency. Mineral nutrition of the trees was slightly affected by irrigation treatments; element concentration in leaves was generally in the optimal range; only potassium showed values below the recommended leaf concentrations. Regarding fruit quality parameters, the vitamin C concentration in RDI showed significant differences with a value of 62.7 mg 100 mL−1 compared to 58.5 mg 100 mL−1 in the control. Plants subjected to SSDI and PRD strategies showed increased levels of pulp colour index with significant values of 10 and 9.90, respectively, compared to the control (8.44). By implementing targeted water management, citrus growers could save water and increase the ascorbic acid and sugar concentration in the fruits; anthocyanins also increased but not significantly. These findings open new market opportunities for citrus growers in marginal areas, where they cannot rely solely on producing citrus fruits to remain competitive.

Ecosystem services of irrigated and controlled drainage agricultural systems: A contemporary global perspective

AbstractIrrigated agriculture provides 40% of the world's crop‐based foods but often with a negative impact on the environment. It is important to recognize that in addition to providing food and fibre, irrigation and controlled drainage systems can be optimized to provide additional ecosystem services and mitigate climate change by using resources in a more efficient way. Contemporary case studies were identified from around the world, including flood control by paddy fields in Japan, water quality enhancement and wastewater reuse in South Africa and Taiwan, micro‐/meso‐climate regulation in Ethiopia and Japan, controlled drainage and sub‐irrigation to maximize carbon sequestration and minimize leaching in Finland, and groundwater table management to reduce irrigation water and pumping requirements in Turkey. Irrigation infrastructure, such as rice paddy terraced landscapes (Japan) and large dams and canals (Australia), have also achieved notable additional ecotourism job creation. Case studies were analysed in terms of funding opportunities and compared using the Common International Classification of Ecosystem Services system. It is recommended that planning frameworks be developed that seek to optimize ecosystem services such as the ones discussed above. Policy should be updated to recognize these services and provide incentives to irrigators and water management entities accordingly.

Effects of water-nitrogen interactions on NH3 and N2O emissions and yield in winter wheat cropland

To investigate the effects of different irrigation and nitrogen application modes on nitrogen gaseous loss in winter wheat farmland, we conducted a field experiment at Changqing Irrigation Experiment Station in Shandong Province, with two irrigation levels (80%-90% θf(I1) and 70%-80% θf(I2)) and three nitrogen application levels (conventional nitrogen application of 240 kg·hm-2(N1), nitrogen reduction of 12.5% (N2), and nitrogen reduction of 25% (N3)). The results showed that ammonia volatilization and nitrous oxide emission rate peak appeared within 2-4 days after fertilization or irrigation. The ammonia volatilization rate during the chasing fertilizer period was significantly higher than that during the basal fertilizer period. Compared with other treatments, the ave-rage ammonia volatilization rate of I2N2 treatment during the chasing fertilizer period was reduced by 10.1%-51.6%, and the average nitrous oxide emission rate over the whole growth period was reduced by 15.4%-52.2%. The ammonia volatilization rate was significantly positively associated with surface soil pH value and ammonium nitrogen content, while the nitrous oxide emission rate was significantly positively associated with nitrate content in topsoil. The accumulation amount of soil ammonia volatilization and nitrous oxide emission ranged from 0.83-1.42 and 0.11-0.33 kg·hm-2, respectively. Moderate reduction of irrigation water and nitrogen input could effectively reduce cumulative amounts of ammonia volatilization and nitrous oxide emission from winter wheat farmland. The cumulative amounts of ammonia volatilization and nitrous oxide emission under I1N3 and I2N2 treatments were signi-ficantly lower than those under other treatments. The highest winter wheat yield (5615.6 kg·hm-2) appeared in I2N2 treatment. The irrigation water utilization efficiency of I2 was significantly higher than that of I1, with the maximum increase rate of 45.2%. Compared with N1 and N3 treatments, the maximum increase rate of nitrogen fertilizer productivity and agricultural utilization efficiency in N2 reached 15.2% and 31.8%, respectively. In conclusion, the treatment with 70%-80% θf irrigation level and 210 kg·hm-2 nitrogen input could effectively improve the utilization efficiency of irrigation water and nitrogen fertilization and reduce gaseous loss from winter wheat farmland.

Fertility and heavy metal pollution in silage maize soil irrigated with different levels of recycled wastewater under conventional and no-tillage practices

AbstractIrrigation with recycled domestic wastewater has been known to obtain positive effects on improving soil fertility, but it may also become a risk factor in case of causing an increase in soil salinity and/or heavy metal concentration of soil. No-tillage can retain soil moisture, helping to reduce irrigation water necessity, and thus lower amounts of heavy metals and salts are added to soil under wastewater irrigation conditions. The objective of this study was to analyze the effects of wastewater irrigation at different levels of on silage maize cultivation under conventional tillage and no-tillage conditions by comparing to full irrigation with fresh water. The two-year experiment was planned according to the split-plots design in the random blocks with three replications. The results indicated that full irrigation with wastewater increased soil salinity, organic matter content, total nitrogen, plant available phosphous, exchangeable cations, exchangeable sodium percentage and soil essential and non-essential heavy metal contents, but decreased soil pH and lime content. Increasing rates in organic matter content, total nitrogen, plant available phosphorus and exchangeable potassium were higher, but in electrical conductivity, and heavy metal accumulation were lower in soil under no-tillage as compared to conventional tillage. Contamination and enrichment factors and geographic accumulation index showed that non-essential heavy metal contamination due to cadmium and nickel, increased in full irrigation with wastewater. Irrigation with wastewater also increased heavy metal accumulation in silage maize. No-tillage can be a recommendable water management practice considering that the risks of soil salinity and heavy metal accumulation can be reduced and that soil fertility can be increased. Also, in reducing the risk of accumulation of cadmium and nickel in soil, 33% deficit irrigation with wastewater can make no-tillage more available.

Assessing the impact of irrigation and nitrogen management on potato performance under varying climate in the state of Florida, USA

Optimizing irrigation and nitrogen (N) fertilizer management in irrigated potato crops grown on sandy soils in subtropical regions such as in northeastern Florida, USA is essential to sustain a high yield and to minimize leaching. N applications in this region typically occur at approximately 25–30 days prior to planting (Npre), at emergence (Neme), and at tuber initiation (Nti). However, recent studies suggest that applying N near planting (Npl) enhances fertilizer N use efficiency (FNUE). We combined experimentation with modeling to assess irrigation and N management options for potato in northeastern Florida. We first aimed to evaluate the DSSAT/CSM-SUBSTOR-Potato model using two-year irrigated field experiments conducted on sandy soils with variable N rates and application timings. CSM-SUBSTOR-Potato accurately simulated aboveground plus tuber dry weight [Relative root mean squared error (RRMSE) = 26.4%, Willmott’s index (d) = 0.98] and N accumulation (RRMSE = 28.6%, d = 0.97). Soil moisture and mineral N were captured well overall, but they were often underestimated due to a water table influence that is currently not considered in DSSAT. Subsequently, CSM-SUBSTOR-Potato was applied to simulate tuber yield, N leaching, and FNUE under scenarios of irrigation scheduling and N-fertilizer application (rate/timing) strategies, focusing on Npre versus Npl aiming to improve resource use efficiency. The simulations indicated that a target of 60% and 70% of the available soil water can be safely used as an irrigation strategy to achieve a high yield, while reducing irrigation water applied and N leached to the environment. Overall Npl increased crop N uptake by 10%, tuber yield by 7%, reduced N leached by 13%, and consequently increasing FNUE by 9%, compared to Npre across the irrigation treatments. Thus, Npl should be preferred in sandy soils and climate-risky subtropical environments, along with Neme and Nti as key timings to synchronize N supply with potato growth.

Sustainable Water Management of Drip-Irrigated Asparagus under Conditions of Central Poland: Evapotranspiration, Water Needs and Rainfall Deficits

Water is a valuable yet scarce resource in agriculture. Optimizing crop production relies on irrigation, but within the framework of sustainable agriculture, efforts should prioritize reducing irrigation water usage. Unfortunately, climate change increases plant water requirements, consequently heightening the need for irrigation. The aim of the research was to estimate the water needs of asparagus during the fern growth period (21 June–31 August) using the Blaney–Criddle method. The study also aimed to determine trends in changing water needs and estimate precipitation deficits. Calculations were carried out for the years 1981–2020 across four provinces in central Poland. The research indicated that water needs varied between 233 mm and 242 mm, depending on the province. Over the forty-year period, all provinces displayed an increasing trend in water needs, with a rise of 3.1 mm to 6.2 mm per decade. Between 21 June and 31 August, rainfall deficits occurred with varying intensity in all provinces during normal, medium dry and very dry years. The values of water needs and rainfall deficit, calculated as a result of the research, are of key importance in the design, construction, and management of drip irrigation systems for asparagus plantations in central Poland.

Climate-smart irrigation strategy can mitigate agricultural water consumption while ensuring food security under a changing climate

North China Plain suffers from the world’s most severe water scarcity and groundwater depletion due to intensive irrigation for agricultural production. It is imperative to reduce irrigation water consumption while safeguarding crop production and food security. This study conducted a quantitative analysis with deficit irrigation strategies for winter wheat using a water-driven AquaCrop model. After model calibration and validation with field experimental data, we analyzed the irrigation water demand, crop yield, and water productivity (WP) of winter wheat under various deficit irrigation scenarios. A set of optimal irrigation schedules were proposed for different climate years, which significantly mitigated irrigation water usage while sustaining high yields and WPs. The results indicated that despite the irrigation water demand of winter wheat under the future climate scenario was slightly higher than that in the historical period, their crop water sensitive periods (reviving, jointing, and flowering) remained the same. Therefore, we recommended adopting the same deficit irrigation schedules for the historical and future periods. In wet years, adopting a 50% deficit irrigation strategy only reduced crop yields by less than 5% compared with full irrigation, but it saved 1000–1100 m3 of water per hectare and contributed a WP higher than 1.88 kg/m3. While in normal and dry years, an optimal 25% deficit irrigation could sustain over 96% of the maximum yield, meanwhile it could save 650–800 m3/ha of water and achieve almost the same WP as full irrigation. These climate-smart irrigation strategies adapting to diverse climatic conditions largely mitigate agricultural water consumption while maximizing crop productivity and water use efficiency, which are essential for achieving precision irrigation and sustainable water management under a changing climate.

Long-Term Study of the Crop Forcing Technique on cv. Tempranillo (Vitis vinifera L.) Vines and Suggested Irrigation Strategies to Improve Water Use Efficiency of Forced Vines

Recently, the crop forcing technique (summer pruning that “forces” the vine to start a new cycle) has proven to be effective in delaying the harvest date and increasing must acidity, but also reducing the yield. However, recent information on deficit irrigation strategies combined with the crop forcing technique reveals that the crop forcing technique reduces irrigation water use efficiency. Two experiments were conducted. Experiment 1 was a 4-year trial to test the effect of the forcing pruning date on the phenology, yield, yield components and water requirements when post-veraison water stress is applied. In this experiment, the treatments were unforced vines (UF-RDI) and forced vines with a forcing pruning date about 70 (F1-RDI) and 100 (F2-RDI) days after budburst. The harvest date was delayed 34 (F1) and 66 (F2) days increasing the must acidity and malic acid concentration in the forced treatments. However, both forced treatments had a reduced yield (36% in F1 and 49% in F2) and irrigation water use efficiency (12% in F1 and 65% in F2). Experiment 2 was a 2-year trial in which irrigation was suppressed before the forcing pruning in F1 (F1-Pre) and F2 (F2-Pre) and after veraison. The yield, yield components, must quality and irrigation were compared to forced vines with irrigation suppression only after veraison (F1-RDI and F2-RDI). For the entire experiment, both treatments in which irrigation was suppressed before the forcing pruning reduced the amount of irrigation supplied (10% in F1-Pre and 30% in F2-Pre) with no negative effects on the yield, yield components or must quality when compared to F-RDI treatments.