Multiple uses of water aquaculture-integrated agriculture systems (AIAS) are inevitable to produce more food per drop of water to address water shortage, food insecurity, and climate change. This survey intends to outline the multiple-use water in pond-based AIAS in light of legal regulations and water salinity. Scenarios for pond-based AIA and their impact on the environment were presented and discussed. Pond-based AIA has been demonstrated to have many social, economic, and environmental benefits. Moreover, international and national experiences and attempts for genuine applications were exhibited. Throughout, pond-based AIA farming practices are seen as a proficient utilization of water that aids food sustainability. It was concluded that pond-based AIA could aid in increasing productivity, income for food producers and soil fertility, ecosystem maintenance, and adaptation to environmental change. AIAS helps adapt to and mitigate climate change by reducing waste and greenhouse gas emissions, reducing pressure on water resources, and recycling nutrients. Finally, developing and promoting the expansion of rotation of wheat-fish and pond-based AIA in the desert and encouraging global collaboration for information and knowledge transfer among different countries were discussed.

Soil salinity and water scarcity adversely affect maize productivity. The use of biochar could enhance soil quality and increase the salt and/or drought threshold tolerance and yield of maize. Therefore, a pot experiment was conducted with three biochar addition rates of 0% (BA₀), 5% (BA₅), and 10% (BA₁₀) concerning salinity stresses of 2.0 (WS₂) and 5.0 dS m⁻¹ (WS₅) under deficit irrigation comprising three levels at 60% (DI₆₀), 75% (DI₇₅), and 100% (DI₁₀₀) of the reference evapotranspiration. Compared with the BA₀ rate, the BA₁₀ rate improved soil properties and the growth, nutrient uptake, and yield of maize. The DI₁₀₀ × SW₂ × BA₁₀ combination improved plant growth, providing the highest yield (257.7 g/plant) and water productivity (WP) (2.92 kg/m³) values. However, the combination DI₆₀ × SW₅ × BA₀ decreased plant growth, offering the lowest yield (121.9 g/plant) and WP (1.96 kg/m³) values. While the former combination increased water and nutrient contents in the soil, the latter combination reduced their values. Considering the salt tolerance index, the yield was more tolerant to salinity stress under the BA₁₀ rate as a 3.60% decrease in yield was detected when soil salinity exceeded the threshold value (5.56 dS/m). The drought threshold was declined from 390 L under BA₀ to 280 L under BA₁₀ rate. The study suggests that biochar could mitigate the adverse effects of deficit irrigation and salinity stress on maize growth and productivity. Thus, biochar could be used in salt-affected soils or when irrigation water is of low quality to sustain maize production.

This study explored the effect of the long-term partial replacement of chemical fertilizer with organic fertilizer on soil organic carbon composition, enzyme activity, and crop yields in the wheat–maize rotation area of northern Anhui, China. This study also specified the proper amount of organic fertilizer replacement that should be used for chemical fertilizer. Different fertilization modes were used (no fertilization, CK; chemical fertilizer, CF; chemical fertilizer and straw returning, CF + S; chemical fertilizer, straw returning, and straw decomposition agent, CF + S + DA; 70% chemical fertilizer and 50% organic fertilizer, 70% CF + 50% OF; 70% chemical fertilizer, 50% organic fertilizer and straw returning, 70% CF + 50% OF + S; 50% chemical fertilizer and 100% organic fertilizer, 50% CF + 100% OF; and 50% chemical fertilizer, 100% organic fertilizer, and straw returning, 50% CF + 100% OF + S). Variations in the organic carbon composition, enzyme activity, soil pH, and crop yields in the wheat–maize rotation under different fertilization treatments were analyzed. The results showed that the replacement of chemical fertilizer with organic fertilizer results in improved crop yields in wheat–maize rotation. The long-term partial replacement of chemical fertilizer with organic fertilizer can increase the quality of soil humus, alleviate soil acidification, and improve soil enzyme activity. Straw returning and organic fertilizer application can considerably raise the activities of urease, acid phosphatase, and nitrate reductase in soil. The soil pH of the CF treatment was reduced compared to the CK treatment, while organic fertilizer application alleviated soil acidification when compared to CF treatment. Organic fertilization increases the total organic carbon content of the soil, which was 19.6~85.5% higher than in the CK treatment. Applying straw and organic fertilizer significantly increased the ratio of the humic/fulvic acid in the soil. The soil active carbon forms of the soil with the application of organic fertilizer and straw returning were significantly higher than those of the CK and CF treatments. This study suggests that the optimal fertilizer management option in northern Anhui’s wheat–maize rotation area is to replace 50% of the chemical fertilizer with organic fertilizer, and to fully return straw to the field. This would include 150 kg N h·m⁻², 60 kg P₂O₅ h·m⁻², 50 kg K₂O h·m⁻², 6000 kg organic fertilizer h·m⁻², and full straw return to the field.