Search

Crop residue returning (CRR) is known to improve the soil environment and thus increase crop production. However, the impacts of CRR on wheat (Triticum aestivum L.) yield have been contrary at times due to the differences in climatic conditions, soil traits, and management practices. These effects were evaluated using 351 paired observations published in 161 papers comprising studies conducted in 19 provinces (autonomous regions) of China. No publication bias or extreme values were found in the data, indicating that the analysis results are highly reliable. Compared with the practice of no crop residue returning (NCRR), the practice of CRR increased wheat yield significantly, on average by 8.29%, and proved more beneficial in Northwest China and in regions with average annual precipitation of 200 to 400 mm, average annual temperatures >11°C, sandy loam soil, and rotation with legumes (soybean [Glycine max (L.) Merr.]–wheat and pea [Pisum sativum L.]–wheat). The following aspects of CRR and crop management conferred greater benefits in yield: continuing the practice for 3 to 6 yr (compared with 1–2, 7–10, and ≥11 yr), using the residues at 3 to 6 t ha−1 (compared with <3, 6–9, and > 9 t ha−1), chopped straw (compared with intact straw), rainfed conditions (compared with irrigated conditions), and applying N at 200 to 300 kg ha−1 (compared with <100, 100–200, and >300 kg ha−1). The yield increase was significantly higher when the residues were returned in the form of mulch (12.56%) and for spring wheat (11.90%) than plowing them back into soil (4.53%) and for winter wheat (7.09%). The meta‐analysis thus confirms the benefits of CRR in higher wheat yields in China and also suggests that the benefits of CRR are site specific. [ABSTRACT FROM AUTHOR]

Water scarcity and high evaporation are critical factors affecting crop growth and yield. Sustainable production of jujube (Ziziphus jujuba Mill.) plantations is essential for economic development and environmental protection in arid desert areas of Northwest China. However, few studies have investigated how plastic film mulching combined with sand tube irrigation (STI) affects soil surface wetted area, soil water indices, crop water consumption, yield, water use efficiency (WUE), and fruit quality in jujube plantations in arid desert areas. Therefore, a 2-year field experiment was conducted with three levels of STI (SW1, 300 m3 ha–1; SW2, 375 m3 ha–1; SW3, 450 m3 ha–1) and surface drip irrigation as a control (DW3, 450 m3 ha–1). Compared with surface drip irrigation, STI significantly decreased (p < 0.05) surface wetted area, and SW3 significantly increased soil water storage in the 60–100 cm layer as well as the 0–100 cm soil layer. Sand tube irrigation also alleviated the soil water deficit in the 60–100 cm soil layer and each soil layer before irrigation and increased yield by 0.6% and WUE by 27.3% on average. The highest yield and WUE were in SW3 in both years. Crop water consumption of jujube trees increased and then decreased during the growth period in both years and reached a maximum in the fruit swelling period. With STI, vitamin C content increased by 9.8%, soluble protein content by 15.6%, and the sugar to acid ratio by 12.2% in both years. Overall, application of STI increased jujube yields and WUE and improved fruit quality by increasing soil water storage and reducing soil water deficit. Thus, this study demonstrates STI can increase economic and ecological benefits, and also provides guidelines to apply STI and improve agricultural water productivity. [Display omitted] • Sand tube irrigation (STI) can increase soil water storage. • STI can improve jujube yield, WUE, and fruit quality. • STI can serve as an ideal alternative irrigation technology in jujube production. • This experiment presented another pathway for agricultural water loss. [ABSTRACT FROM AUTHOR]

Efficient water-saving irrigation techniques and appropriate nitrogen (N) application are keys to solving the problems of water scarcity and irrational fertilization in jujube cultivation. In this study, first, the effects of sand tube irrigation (STI) on surface and subsurface wetted characteristics were investigated using in-situ infiltration tests in a jujube garden. Compared with surface drip irrigation (SD), STI reduced surface wetted area by 57.4% and wetted perimeter of the surface wetted circle by 37.1% and increased subsurface maximum infiltration distance of wetting front by 64.9%. At the optimal sand tube depth of 20 cm, surface wetted area of the surface wetted circle decreased by 65.4% and maximum infiltration distance of the wetting front increased by 70.9%, compared with SD. Two-year field experiments then investigated the effects of STI and SD on soil water storage, jujube leaf chlorophyll, net photosynthetic rate, actual water consumption, fruit yield, and water (WUE) and N (NUE) use efficiencies at four levels of N (pure nitrogen: N1, 0; N2, 286 kg ha -1 ; N3, 381 kg ha -1 ; N4, 476 kg ha -1 ) at the same irrigation amount (45 mm irrigation -1 , total of 8). Compared with SD, STI increased soil water storage 18.0% (2021) and 15.6% (2022) during the entire growth period and also chlorophyll content, nitrogen balance index, and net photosynthetic rate, with both increasing and then decreasing with increasing N. Compared with SD, STI increased yields by 39.1% and 36.5% and WUE by 44.3% and 39.7% in 2021 and 2022, respectively. Nitrogen use efficiency was 2.5 (2021) and 1.6 (2022) times higher with STI than with SD. STI combined with N3 had the highest yield, WUE, NUE, and net income and is thus recommended as the optimal water-N combination. In conclusion, STI combined with appropriate N application can be an effective water-saving irrigation technology alternative to SD in jujube cultivation in arid areas., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Bai, Zhang, Jia, Sun, Zhang, Zhao, Fang, Wang, Xu and Cao.)