Water-Saving Potential of Subsurface Drip Irrigation For Winter Wheat

Muhammad Umair,Yucui Zhang,Leilei Min,Yongqing Qi,Ayesha Ahmad,Yanjun Shen,Jiawei Yao,Hanbing Jiang,Tabassum Hussain

doi:10.3390/su11102978

Abstract

Groundwater plays a major role in agro-hydrological processes in the North China Plain (NCP). The NCP is facing a water deficit, due to a rapid decline in the water table because of the double cropping system. A two crop (maize and wheat) rotation is required to balance the food supply and demand, which leads to an imbalance between evapotranspiration (ET) and precipitation. Thus, there has been a decline of about 1.35 m yr−1 of groundwater (Luancheng Agroecosystem Experimental Station (LAES), NCP) during the last 10 years. Lysimeter experiments were conducted under different irrigation treatments (flood, surface drip, and subsurface drip) to account for ET in the selection of a suitable irrigation method. Subsurface drip irrigation reduced ET by 26% compared to flood irrigation, and 15% compared to surface drip irrigation, with significant grain yield and biomass formation due to decreased evaporation losses. Grain yield, yield components, and above ground biomass were similar in subsurface drip and flood irrigation. However, these biomass parameters were lower with surface drip irrigation. Furthermore, subsurface drip irrigation increased the crop water productivity (24.95%) and irrigation water productivity (19.59%) compared to flood irrigation. The subsurface irrigated plants showed an increase in net photosynthesis (~10%), higher intrinsic water use efficiency (~36%), lower transpiration rate (~22%), and saved 80 mm of water compared to flood irrigation. Our findings indicate that subsurface drip irrigation can be adopted in the NCP to increase water use efficiency, optimize grain yield, and minimize water loss in order to address scarcity.

Highlights

The rising world population is increasing pressure on the food system
The temporal trends in ET of different irrigation methods (i.e., Flood Irrigation (FI), Surface Drip Irrigation (SDI), and subsurface drip irrigation (SSDI)) throughout the growth season for winter wheat (WW) from planting to harvesting are shown in Figure 5 and it is clearly illustrated that the most eminent total ET was found in FI and the lowest in SSDI
Grain yield was increased by 5.68% in FI and 3.41% in SSDI relative to the yield in SDI

Summary

Introduction

The rising world population is increasing pressure on the food system. It is expected that food demand will increase by about 70% by 2050 [1], making effective water planning and management critical. The North China Plain (NCP) is a major grain production zone that plays a critical role in ensuring China’s food supply. The double cropping system is one of the many hydrological threats to the water table across the globe, and especially in the Hebei Plain, NCP. The mean water deficit (P − ET) for the wheat crop period varies from 160 to 410 mm at the Luancheng Agroecosystem Experimental Station, Chinese Academy of Science (LAES-CAS) in the NCP [7]. The past 28-year winter wheat (WW) experiment in the LAES-CAS showed that seasonal rainfall is decreasing, but atmospheric evaporation is increasing [8]

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Conclusion