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Data extracted in January 2023
Fiche created in September 2023
Note to the reader: This general fiche summarises all the environmental and climate impacts of WATER-SAVING IRRIGATION PRACTICES IN NON-FLOODED LANDS found in a review of 26 synthesis papers[1]. These papers were selected from an initial number of 660 obtained through a systematic literature search strategy, according to the inclusion criteria reported in section 4. The impacts reported here are those for which there is scientific evidence available in published synthesis papers, what does not preclude the farming practice to have other impacts on the environment and climate still not covered by primary studies or by synthesis papers.
The synthesis papers review a number of primary studies ranging from 19 to 473. Therefore, the assessment of impacts relies on a large number of results from the primary studies, obtained mainly in field conditions, or sometimes in lab experiments or from model simulations.
1. DESCRIPTION OF THE FARMING PRACTICE
- Description:
- Water-saving irrigation practices aim to satisfy crop water requirements while improving the timing and reliability of water deliveries to minimize water use.[2]
- Non water-saving irrigation practices are standard techniques of irrigation that supply water to the crop in order to increasing crop productivity, with no intention of minimizing water use.[3]
- Key descriptors:
- Water-saving irrigation practices in non-flooded lands included in this review are:
- aerated irrigation: irrigation practice characterised by the delivery of aerated water directly to the root zone by subsurface drip irrigation.[4]
- deficit irrigation: an irrigation practice whereby water supply is reduced below maximum levels and mild stress is allowed with minimal effects on yield.[5]
- optimised irrigation period: irrigation during crucial stages of the growing season.[6]
- partial root-zone drying: a modified version of deficit irrigation where approximately half of the root system is in a dry state, while the remaining half is irrigated.[7]
- reduced irrigation amount: reducing the amount of water used for irrigation.[8]
- drip irrigation: water is dripped onto the soil at very low rates (2-20 litres/hour) from a system of small diameter plastic pipes fitted with outlets called emitters or drippers. Water can be applied at the surface (surface drip irrigation) or underground (subsurface drip irrigation).[9]
- irrigation using water from other source: irrigation using reclaimed, brackish, saline, or treated waste water rather than fresh water.[10]
- In this review, these practices are compared to
- non-water saving irrigation practices in non-flooded lands, such as sprinkler irrigation, furrow irrigation, center pivot irrigation, full or supplemental irrigation
- or to an alternative water-saving irrigation practice in non-flooded lands.
- This review does not present the results of the comparisons between non water-saving irrigation practices and continuous flooding in flooded lands and between no irrigation and non-water saving irrigation practices as these comparisons are presented in two separate sets of fiches entitled “Water-saving irrigation practices in flooded lands” and “No irrigation”, respectively.
- This review does not include irrigation practices applied in non-agricultural land.
- Water-saving irrigation practices in non-flooded lands included in this review are:
2. EFFECTS OF THE FARMING PRACTICE ON CLIMATE AND ENVIRONMENTAL IMPACTS
We reviewed the impacts of water-saving irrigation practices in non-flooded lands when compared to different comparators. Table 1a reports the impacts when compared to non water-saving irrigation practices in non-flooded lands. Table 1b shows the impacts when compared to other water-saving irrigation practices.
The table below shows the number of synthesis papers with statistical tests reporting i) a significant difference between the Intervention and the Comparator, that is to say, a significant statistical effect, which can be positive or negative; or ii) a non-statistically significant difference between the Intervention and the Comparator. In addition, we include, if any, the number of synthesis papers reporting relevant results but without statistical test of the effects. Details on the quality assessment of the synthesis papers can be found in the methodology section of this WIKI.
Out of the 26 selected synthesis papers, 18 included studies conducted in Europe, and 26 have a quality score higher than 50%.
Table 1a: Summary of effects of water-saving irrigation practices compared to non water-saving irrigation practices. Number of synthesis papers reporting positive, negative or non-statistically significant effects on environmental and climate impacts. The number of synthesis papers reporting relevant results but without statistical test of the effects are also provided. When not all the synthesis papers reporting an effect are of high quality, the number of synthesis papers with a quality score of at least 50% is indicated in parentheses. Some synthesis papers may report effects for more than one impact, or more than one effect for the same impact.
Statistically tested | Non-statistically tested | ||||||
Impact | Metric | Intervention | Comparator | Significantly positive | Significantly negative | Non-significant | |
Decrease GHG emissions | N2O emission | Water-saving irrigation practices | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 |
Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Drip irrigation | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Decrease Global warming potential (LCA) | Yield-scaled GHG emissions | Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 |
Optimised irrigation period | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Decrease Nutrient leaching and run-off | Nitrate leaching | Water-saving irrigation practices | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 |
Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Optimised irrigation period | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Deficit irrigation | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Increase Plant nutrient uptake | Nutrient use efficiency | Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 0 | 1 | 1 | 0 |
Increase Soil physico-chemical quality | Salinity | Irrigation using water from other source | Non water-saving irrigation practices in non-flooded lands | 0 | 1 | 1 | 0 |
Increase Soil water retention | Soil water content | Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 |
Optimised irrigation period | Non water-saving irrigation practices in non-flooded lands | 0 | 0 | 1 | 0 | ||
Decrease Water footprint (LCA) | Grey water footprint | Water-saving irrigation practices | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 |
Decrease Water use | Water use efficiency | Water-saving irrigation practices | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 |
Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 1 | 1 | 1 | 0 | ||
Optimised irrigation period | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Deficit irrigation | Non water-saving irrigation practices in non-flooded lands | 10 | 1 | 2 | 0 | ||
Partial root-zone drying | Non water-saving irrigation practices in non-flooded lands | 2 | 0 | 0 | 0 | ||
Aerated irrigation | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Irrigation using water from other source | Non water-saving irrigation practices in non-flooded lands | 0 | 1 | 0 | 0 | ||
Water input | Water-saving irrigation practices | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | |
Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Optimised irrigation period | Non water-saving irrigation practices in non-flooded lands | 0 | 0 | 1 | 0 | ||
Increase Crop yield | Crop yield | Water-saving irrigation practices | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 1 | 0 |
Improved irrigation technology (using more efficient systems for water delivery) | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Reduced irrigation amount | Non water-saving irrigation practices in non-flooded lands | 0 | 1 | 3 | 0 | ||
Optimised irrigation period | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 1 | 1 | ||
Deficit irrigation | Non water-saving irrigation practices in non-flooded lands | 0 | 11 | 1 | 0 | ||
Partial root-zone drying | Non water-saving irrigation practices in non-flooded lands | 0 | 2 | 0 | 0 | ||
Aerated irrigation | Non water-saving irrigation practices in non-flooded lands | 1 | 0 | 0 | 0 | ||
Irrigation using water from other source | Non water-saving irrigation practices in non-flooded lands | 1 | 2 | 1 | 0 | ||
Table 1b: Summary of effects of water-saving irrigation practices compared to other water-saving irrigation practices. Number of synthesis papers reporting positive, negative or non-statistically significant effects on environmental and climate impacts. The number of synthesis papers reporting relevant results but without statistical test of the effects are also provided. When not all the synthesis papers reporting an effect are of high quality, the number of synthesis papers with a quality score of at least 50% is indicated in parentheses. Some synthesis papers may report effects for more than one impact, or more than one effect for the same impact.
Statistically tested | Non-statistically tested | ||||||
Impact | Metric | Intervention | Comparator | Significantly positive | Significantly negative | Non-significant | |
Decrease GHG emissions | N2O emission | Subsurface drip irrigation using microsprinkler | Subsurface drip irrigation without microsprinkler | 1 | 0 | 0 | 0 |
Decrease Water use | Water use efficiency | Subsurface drip irrigation | Surface drip irrigation | 1 | 0 | 0 | 0 |
Partial root-zone drying | Deficit irrigation | 1 | 0 | 1 | 0 | ||
Severe deficit irrigation | Deficit irrigation | 0 | 0 | 1 | 0 | ||
Increase Crop yield | Crop yield | Subsurface drip irrigation | Surface drip irrigation | 1 | 0 | 0 | 0 |
Partial root-zone drying | Deficit irrigation | 0 | 0 | 2 | 0 | ||
Severe deficit irrigation | Deficit irrigation | 0 | 1 | 0 | 0 | ||
3. FACTORS INFLUENCING THE EFFECTS ON CLIMATE AND ENVIRONMENTAL IMPACTS
The factors significantly influencing the size and/or direction of the effects on the impacts, according to the synthesis papers included in this review, are reported below. Details about the factors can be found in the summaries of the meta-analyses available in this WIKI.
Table 2: List of factors reported to significantly affect the size and/or direction of the effects on environmental and climate impacts, according to the synthesis papers reviewed. The reference number of the synthesis papers where those factors are explored is given in parentheses.
Impact | Factors |
GHG emissions | Crop type (Ref14), Proportion of water reduction (Ref14) and Soil type (Ref14) |
Global warming potential (LCA) | Water management (Ref25) |
Nutrient leaching and run-off | Water management (Ref25) |
Plant nutrient uptake | Water management (Ref25) |
Soil physico-chemical quality | Crop type (Ref14), Proportion of water reduction (Ref14) and Soil type (Ref14) |
Soil water retention | Water management (Ref25) |
Water footprint (LCA) | Water management (Ref25) |
Water use | Aerated method (Ref22), Aerated quantity (Ref22), Burial depth of subsurface tubing (Ref22), Climate (Ref2, Ref4, Ref5, Ref9, Ref12, Ref12), Crop growing cycle (Ref2), Crop type (Ref4, Ref5, Ref7, Ref8, Ref26, Ref26), Deficit irrigation stress (Ref2), Degree of irrigation deficit (Ref4), Drip irrigation parameters (Ref5), Fertilisation rate (Ref2, Ref5), Growth stage (Ref2, Ref4), Irrigation method (Ref4, Ref15), Irrigation stages (Ref3, Ref15), Irrigation times (Ref3, Ref19), Irrigation volume (Ref3, Ref15), Planting conditions and patterns (Ref5), Precipitations (Ref3, Ref15), Region/geographic area (Ref3), Soil bulk density (Ref4, Ref22), Soil characteristics (Ref5, Ref15), Soil pH (Ref22), Soil texture (Ref4, Ref7, Ref19, Ref22), Soil texture and soil type (Ref2, Ref8) and Water management (Ref7, Ref9, Ref22) |
Crop yield | Aerated method (Ref22), Aerated quantity (Ref22), Burial depth of subsurface tubing (Ref22), Climate (Ref2, Ref4, Ref5, Ref9, Ref12, Ref15), Crop growing cycle (Ref2), Crop type (Ref1, Ref4, Ref5, Ref7, Ref8, Ref20), Cultivation years (Ref1), Deficit irrigation stress (Ref2), Degree of irrigation deficit (Ref4), Drip irrigation parameters (Ref5), Fertilisation rate (Ref2, Ref5), Growth stage (Ref2, Ref4), Irrigation method (Ref1, Ref4, Ref15), Irrigation stages (Ref3, Ref15), Irrigation times (Ref3, Ref19), Irrigation volume (Ref1, Ref3, Ref12, Ref15), Planting conditions and patterns (Ref5), Precipitations (Ref3, Ref15), Reclaimed water quality (Ref1), Region/geographic area (Ref3), Soil bulk density (Ref4, Ref22), Soil characteristics (Ref5, Ref15), Soil pH (Ref7, Ref22), Soil texture (Ref4, Ref7, Ref12, Ref19, Ref20, Ref22, Ref24), Soil texture and soil type (Ref8) and Water management (Ref7, Ref9, Ref22) |
4. SYSTEMATIC REVIEW SEARCH STRATEGY
Table 3: Systematic review search strategy - methodology and search parameters.
Parameter | Details |
Keywords | WOS: ((TS=((((“sustainab*” OR “improv*” OR “reduc*” OR “limit*” OR “deficit*” OR “efficien*”) NEAR “irrigat*”) OR ((“sustainab*” OR “improv*”) NEAR ((“water” NEAR (“use” OR “reuse”)) OR “water use efficiency” OR “WUE” OR “water productivity” OR “water harvest*” OR “water balance” OR “water quality” OR “water uptake” OR “water holding capacity”)) OR ((“sustainab*” OR “improv*”) NEAR (“water” NEAR (“management” OR “storage” OR “retention” OR “conservation” OR “infiltration”))) OR ((“sustainab*” OR “improv*”) NEAR (“water” NEAR (“blueprint” OR “footprint”)))) )) AND |
Time reference | No time restriction. |
Databases | Web of Science and Scopus: run on 24 January 2023 |
Exclusion criteria | The main criteria that led to the exclusion of a synthesis paper are: 2) The paper is neither a systematic review nor a meta-analysis of primary research, 3) The analysis is not based on pairwise comparisons, 4) The paper is not written in English, 5) The full text is not available and 6) The intervention (water-saving irrigation practices in non-flooded lands) and/or comparator (non water-saving irrigation practice OR another water-saving irrigation practice in non-flooded lands) are not clear. |
5. SYNTHESIS PAPERS INCLUDED IN THE REVIEW
Table 4: List of synthesis papers included in this review. More details can be found in the summaries of the meta-analyses.
Ref Num | Author(s) | Year | Title | Journal | DOI |
Ref1 | Liu, XF; Zhang, L; Yang, FH; Zhou, W | 2023 | Determining reclaimed water quality thresholds and farming practices to improve food crop yield: A meta-analysis combined with random forest model | Science of The Total Environment, 862, 160774 | 10.1016/j.scitotenv.2022.160774 |
Ref2 | Allakonon M.G.B., Zakari S., Tovihoudji P.G., Fatondji A.S., Akponikpè P.B.I. | 2022 | Grain yield, actual evapotranspiration and water productivity responses of maize crop to deficit irrigation: A global meta-analysis | Agricultural water management, 270, 107746 | 10.1016/j.agwat.2022.107746 |
Ref3 | Li, Q; Chen, Y; Sun, SK; Zhu, MY; Xue, J; Gao, ZH; Zhao, JF; Tang, YH | 2022 | Research on Crop Irrigation Schedules Under Deficit Irrigation-A Meta-analysis | Water resources management, 36(12), 4799-4817 | 10.1007/s11269-022-03278-y |
Ref4 | Tong, XY; Wu, PT; Liu, XF; Zhang, L; Zhou, W; Wang, ZG | 2022 | A global meta-analysis of fruit tree yield and water use efficiency under deficit irrigation | Agricultural water management, 260, 107321 | 10.1016/j.agwat.2021.107321 |
Ref5 | Wang, HD; Wang, NJ; Quan, H; Zhang, FC; Fan, JL; Feng, H; Cheng, MH; Liao, ZQ; Wang, XK; Xiang, YZ | 2022 | Yield and water productivity of crops, vegetables and fruits under subsurface drip irrigation: A global meta-analysis | Agricultural water management, 269, 107645 | 10.1016/j.agwat.2022.107645 |
Ref6 | Yao, CC; Wu, XW; Bai, H; Gu, JX | 2022 | Nitrous Oxide Emission and Grain Yield in Chinese Winter Wheat-Summer Maize Rotation: A Meta-Analysis | Agronomy, 12(10), 2305 | 10.3390/agronomy12102305 |
Ref7 | Cheng, MH; Wang, HD; Fan, JL; Wang, XK; Sun, X; Yang, L; Zhang, SH; Xiang, YZ; Zhang, FC | 2021 | Crop yield and water productivity under salty water irrigation: A global meta-analysis | Agricultural water management, 256, 107105 | 10.1016/j.agwat.2021.107105 |
Ref8 | Cheng, MH; Wang, HD; Fan, JL; Zhang, SH; Liao, ZQ; Zhang, FC; Wang, YL | 2021 | A global meta-analysis of yield and water use efficiency of crops, vegetables and fruits under full, deficit and alternate partial root-zone irrigation | Agricultural water management 248, 106771 | 10.1016/j.agwat.2021.106771 |
Ref9 | Cheng, MH; Wang, HD; Fan, JL; Zhang, SH; Wang, YL; Li, YP; Sun, X; Yang, L; Zhang, FC | 2021 | Water productivity and seed cotton yield in response to deficit irrigation: A global meta-analysis | Agricultural water management 255, 107027 | 10.1016/j.agwat.2021.107027 |
Ref10 | Gao, Y; Shao, GC; Wu, SQ; Xiaojun, W; Lu, J; Cui, JT | 2021 | Changes in soil salinity under treated wastewater irrigation: A meta-analysis | Agricultural water management, 255, 106986 | 10.1016/j.agwat.2021.106986 |
Ref11 | Kuang, WN; Gao, XP; Tenuta, M; Zeng, FJ | 2021 | A global meta-analysis of nitrous oxide emission from drip-irrigated cropping system | Global change biology 27, 3244-3256 | 10.1111/gcb.15636 |
Ref12 | Singh, M; Singh, P; Singh, S; Saini, RK; Angadi, SV | 2021 | A global meta-analysis of yield and water productivity responses of vegetables to deficit irrigation | Scientific reports 11, 22095 | 10.1038/s41598-021-01433-w |
Ref13 | Bai, XL; Zhang, ZB; Cui, JJ; Liu, ZJ; Chen, ZJ; Zhou, JB | 2020 | Strategies to mitigate nitrate leaching in vegetable production in China: a meta-analysis | Environmental Science and Pollution Research, 27, 18382-18391 | 10.1007/s11356-020-08322-1 |
Ref14 | Gu, JX; Wu, YY; Tian, ZY; Xu, HH | 2020 | Nitrogen use efficiency, crop water productivity and nitrous oxide emissions from Chinese greenhouse vegetables: A meta-analysis | Science of the total environment 743: 140696 | 10.1016/j.scitotenv.2020.140696 |
Ref15 | Yu, LY; Zhao, XN; Gao, XD; Siddique, KHM | 2020 | Improving/maintaining water-use efficiency and yield of wheat by deficit irrigation: A global meta-analysis | Agricultural water management, 228, 105906 | 10.1016/j.agwat.2019.105906 |
Ref16 | Zhang, Y; Liu, XJ; You, LZ; Zhang, FS | 2020 | Improving potential of nitrogen linked gray water footprint in China's intensive cropping systems | Journal of Cleaner Production, 269, 122307 | 10.1016/j.jclepro.2020.122307 |
Ref17 | Zheng, HF; Shao, RX; Xue, YF; Ying, H; Yin, YL; Cui, ZL; Yang, QH | 2020 | Water productivity of irrigated maize production systems in Northern China: A meta-analysis | Agricultural water management, 234, 106119 | 10.1016/j.agwat.2020.106119 |
Ref18 | Gu J., Nie H., Guo H., Xu H., Gunnathorn T. | 2019 | Nitrous oxide emissions from fruit orchards: A review | Atmospheric environment, 201, 166-172 | 10.1016/j.atmosenv.2018.12.046 |
Ref19 | Lu, J; Shao, GC; Cui, JT; Wang, XJ; Keabetswe, L | 2019 | Yield, fruit quality and water use efficiency of tomato for processing under regulated deficit irrigation: A meta-analysis | Agricultural water management, 222, 301-312 | 10.1016/j.agwat.2019.06.008 |
Ref20 | Adu, MO; Yawson, DO; Armah, FA; Asare, PA; Frimpong, KA | 2018 | Meta-analysis of crop yields of full, deficit, and partial root-zone drying irrigation | Agricultural water management, 197, 79-90 | 10.1016/j.agwat.2017.11.019 |
Ref21 | Du, YD; Niu, WQ; Gu, XB; Zhang, Q; Cui, BJ | 2018 | Water- and nitrogen-saving potentials in tomato production: A meta-analysis | Agricultural water management, 210, 158-164 | 10.1016/j.agwat.2018.08.035 |
Ref22 | Du, YD; Niu, WQ; Gu, XB; Zhang, Q; Cui, BJ; Zhao, Y | 2018 | Crop yield and water use efficiency under aerated irrigation: A meta-analysis | Agricultural water management, 210, 158-164 | 10.1016/j.agwat.2018.07.038 |
Ref23 | Zheng, HF; Bian, QQ; Yin, YL; Ying, H; Yang, QH; Cui, ZL | 2018 | Closing water productivity gaps to achieve food and water security for a global maize supply | Scientific reports, 8(1), 14762 | 10.1038/s41598-018-32964-4 |
Ref24 | He, G; Cui, ZL; Ying, H; Zheng, HF; Wang, ZH; Zhang, FS | 2017 | Managing the trade-offs among yield increase, water resources inputs and greenhouse gas emissions in irrigated wheat production systems | Journal of Cleaner Production, 164, 567-574 | 10.1016/j.jclepro.2017.06.085 |
Ref25 | Quemada, M; Baranski, M; Nobel-de Lange, MNJ; Vallejo, A; Cooper, JM | 2013 | Meta-analysis of strategies to control nitrate leaching in irrigated agricultural systems and their effects on crop yield | Agriculture, ecosystems & environment, 174, 1-10 | 10.1016/j.agee.2013.04.018 |
Ref26 | Sadras, VO | 2009 | Does partial root-zone drying improve irrigation water productivity in the field? A meta-analysis | Irrigation science, 27, 183-190 | 10.1007/s00271-008-0141-0 |
Disclaimer: These fiches present a large amount of scientific knowledge synthesised to assess farming practices impacts on the environment, climate and productivity. The European Commission maintains this WIKI to enhance public access to information about its initiatives. Our goal is to keep this information timely and accurate. If errors are brought to our attention, we will try to correct them. However, the Commission accepts no responsibility or liability whatsoever with regard to the information on these fiches and WIKI.
[1] Synthesis research papers include either meta-analysis or systematic reviews with quantitative results. Details can be found in the methodology section of the WIKI.
[2] FAO, 2017. Does improved irrigation technology save water? Available at: https://www.fao.org/3/I7090EN/i7090en.pdf
[3] European Parliamentary Research Service, 2019. Irrigation in EU agriculture. Available at: https://www.europarl.europa.eu/RegData/etudes/BRIE/2019/644216/EPRS_BRI(2019)644216_EN.pdf
[4] Du, Y. D., Niu, W. Q., Gu, X. B., Zhang, Q., Cui, B. J., & Zhao, Y. (2018). Crop yield and water use efficiency under aerated irrigation: A meta-analysis. Agricultural Water Management, 210, 158-164.
[5] Unlocking the Water Potential of Agriculture, FAO, 2003.
[6] e.g. He, G., Cui, Z., Ying, H., Zheng, H., Wang, Z., & Zhang, F. (2017). Managing the trade-offs among yield increase, water resources inputs and greenhouse gas emissions in irrigated wheat production systems. Journal of Cleaner Production, 164, 567-574; Quemada, M., Baranski, M., Nobel-de Lange, M. N. J., Vallejo, A., & Cooper, J. M. (2013). Meta-analysis of strategies to control nitrate leaching in irrigated agricultural systems and their effects on crop yield. Agriculture, ecosystems & environment, 174, 1-10.
[7] Sonawane, A.V. & Shrivastava, P.K. (2022) Partial root zone drying method of irrigation: A review. Irrigation and Drainage, 71( 3), 574– 588. doi:10.1002/ird.2686
[8] e.g. He, G., Cui, Z., Ying, H., Zheng, H., Wang, Z., & Zhang, F. (2017). Managing the trade-offs among yield increase, water resources inputs and greenhouse gas emissions in irrigated wheat production systems. Journal of Cleaner Production, 164, 567-574; Du, Y. D., Niu, W. Q., Gu, X. B., Zhang, Q., Cui, B. J., & Zhao, Y. (2018). Crop yield and water use efficiency under aerated irrigation: A meta-analysis. Agricultural Water Management, 210, 158-164; Bai, X., Zhang, Z., Cui, J., Liu, Z., Chen, Z., & Zhou, J. (2020). Strategies to mitigate nitrate leaching in vegetable production in China: a meta-analysis. Environmental Science and Pollution Research, 27, 18382-18391.
[9] FAO, Irrigation Water Management: Irrigation Methods. Training manual no 5
[10] e.g. Liu, X., Zhang, L., Yang, F., & Zhou, W. (2023). Determining reclaimed water quality thresholds and farming practices to improve food crop yield: A meta-analysis combined with random forest model. Science of The Total Environment, 862, 160774; Cheng, M., Wang, H., Fan, J., Wang, X., Sun, X., Yang, L., … & Zhang, F. (2021). Crop yield and water productivity under salty water irrigation: A global meta-analysis. Agricultural Water Management, 256, 107105; Gao, Y., Shao, G., Wu, S., Xiaojun, W., Lu, J., & Cui, J. (2021). Changes in soil salinity under treated wastewater irrigation: A meta-analysis. Agricultural Water Management, 255, 106986.