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Conventional farming practices not only constrained food security due to low yield but also threatened the ecosystem by causing groundwater decline and groundwater nitrate contamination. A two׹ear field experiment was conducted at the research station of North China University of Water Resources and Electric Power, Zhengzhou. The WHCNS model was used to simulate grain yield, water and nitrogen fertilizer use efficiencies (WUE and FNUEs) of spring maize under border irrigation method, drip irrigation, and rainfed conditions. In addition, a scenario analysis was also performed on different dry and rainy seasons to assess the long-term impact of rainfall variability on spring maize from 2000–2017. The result showed that the model precisely simulated soil water content, N concentration, crop biomass accumulation, and grain yield. The maximum and minimum range of relative root mean squire error (RRMSE) values were 0.5–36.0% for soil water content, 14.0–38.0% for soil nitrate concentrations, 19.0–24.0% for crop biomass and 1.0–2.0% for grain yield, respectively under three irrigation methods. Both the index of agreement (IA) and Pearson correlation coefficient (r) values were close 1. We found the lowest grain yield from the rainfed maize, whereas the drip irrigation method increased grain yield by 14% at 40% water saving than border irrigation method for the two years with the 11% lower evaporation and maintained transpiration rate. Moreover, the drip irrigated maize had a negligible amount of drainage and runoff, which subsequently improved WUE by 27% in the first growing season and 16% in the second rotation than border irrigation. The drip irrigated maize also showed 24% higher FNUE. The reason of lower WUE and FNUEs under the border irrigation method was increased drainage amounts and N leaching rates. Furthermore, scenario analysis indicated that the dry season could result in a 30.8% yield decline as compared to rainy season.

Backgrounds: Drought stress is one of the major factors that affects maize yield. ZF-HD transcription factors have been proved to play pivotal roles in the regulation of plant growth, hormone conduction signaling and abiotic stress response. However, the molecular mechanism of ZmZHD9-mediated drought tolerance is not well understood. Results: In the present study, we analyzed the functions of ZmZHD9, a member of the maize ZF-HD family. ZmZHD9 is predominantly expressed in leaves, and was induced by drought, salinity, high temperature and abscisic acid (ABA). Subcellular localization indicated that ZmZHD9 protein was localized in the nucleus. ZmZHD9-overexpressing plants showed increased tolerance to drought stress compared with wild-type plants, evaluated by higher RWC and proline content, higher SOD and POD activity, lower REL and MDA content in transgenic plants under drought stress. In addition, the expression of six stress-responsive genes were significantly higher in ZmZHD9 transgenic plants than that in wild-type plants under drought stress.Conclusion: These results demonstrate that ZmZHD9 as a stress-responsive transcription factor which plays a positive regulatory role in response to drought.

A field experiment was conducted to explore the effect of different sowing time and seeding rate on yield components and water use efficiency (WUE) of winter wheat by regulating the growth redundancy and physiological traits of root and shoot. Winter wheat sowing was performed on Oct.12 (T1), Oct.22 (T2), Nov.3 (T3), respectively. There were three treatments of different seeding rates, i.e. 112.5 kg hm−2 (D1), 150 kg hm−2 (D2) and 225 kg hm−2(D3) in each sowing time. The results showed that sowing time and seeding rate significantly influenced the morphological and physiological characteristics of winter wheat. Plant height, ineffective tiller number, leaf area and root biomass decreased significantly along with the delay of sowing date. Plant height, ineffective tiller number and root biomass increased significantly and leaf area decreased significantly with increasing seeding rate. Under the same seeding rate condition, T1 had the highest number of ineffective tiller, and T3 had the lowest one. Delayed sowing (T2 and T3) increased significantly root activities and leaf photosynthetic rate (Pn) in the late growing stage, and decreased significantly root respiration rate (Rroot) per unit area of wheat. In the same sowing time treatment, root activities and leaf Pn decreased significantly and Rroot increased significantly with the increase of seeding rate; however, seeding rate had no effect on root activity and leaf Pn in T3 treatment. Grain yield decreased significantly in T1 and increased significantly in T3 with the increase of seeding rate, and it was the highest in D2 and the lowest in D1 in T2 treatment. Delayed sowing lowered significantly soil water consumption of crop. Under the same sowing time condition, soil water consumption increased significantly as seeding rate increased. WUE decreased significantly with the increase of seeding rate in T1and T2 treatments. In two test years, T2D2 had highest grain yield and WUE, and T3D1 had lowest grain yield and WUE. The interaction of sowing time and seeding rate also had significant effect on soil water consumption, grain yield and WUE. It is clear that appropriate sowing time and seeding rate (T2 Treatmeat) can increase grain yield and WUE of winter wheat by regulating the growth redundancy and physiological traits of root and shoot, but excessive reduction of vegetative organs (T3 Treatmeat) can affect crop production.

Excessive water and fertilizer input in conventional farming practices not only lead to low production but also damaged the ecosystem by causing groundwater decline and groundwater nitrate contamination. The two-year field experiments were conducted at Zhengzhou of China and TandoJam of Pakistan sites, respectively. The WHCNS (soil-water-heat-carbon-nitrogen-simulator) model was used to simulate soil water dynamic, nitrogen (N) fate and maize yield under different irrigation practices, including farmer-based full flood irrigation (FI), drip irrigation (DI) and rainfed (RF) at the Zhengzhou site. Treatments of the TandoJam site were full flood irrigation (F100), moderate deficit irrigation (F75) and high deficit irrigation (F50) to meet the 100%, 75% and 50% crop evapotranspiration, respectively. Results showed that the model precisely simulated water consumption, fates of N, crop growth, and yield at both sites. In Zhengzhou site, we found the lowest grain yield in the RF system, whereas the DI increased average grain yield by 9.8%, decreased 62.5% water consumption compared to FI for the two years. Moreover, the DI had a negligible amount of drainage, runoff, and N leaching, which subsequently improved water use efficiency (WUE) up-to 24.5% and 9.1% fertilizer N use efficiency (FNUE). In TandoJam site, compared to F100, the F75 produced almost equal grain yield with 25.1% water-saving, reduced 42.5% drainage and 11.8% runoff, 57% N leaching, enhanced 4.1% WUE and 14.9% FNUE. Furthermore, results suggested that too deficit irrigation, for example, F50, could cause serious yield loss or complete crop failure, because the weather condition of the TandoJam site is very hot.

Understanding the temporal and spatial patterns of soil water extraction and their impacts on growth response of winter wheat to deficit subsurface drip irrigation (SDI) conditions is critical for managing water scarcity and stabilizing yield. A field experiment was conducted from 2016 to 2018 involving five SDI amounts: 0.25 ETc, 0.4 ETc, 0.6 ETc, 0.8 ETc, and 1.0 ETc, representing 25%, 40%, 60%, 80%, and 100% of crop evapotranspiration (ETc), respectively. The results showed that the 0.6 ETc treatment significantly increased soil water extraction from 40–80-cm and 80–140-cm from jointing to maturity as compared to the 1.0 ETc treatment. Whereas the 0.8 ETc treatment significantly increased soil water extraction from 80–140-cm deep soil from flowering to maturity in the first growing season. The crop was most water-stressed under the 0.25 ETc and 0.4 ETc treatments, thus extracted more soil water from 0–140-cm soil profile. However, both treatments exhibited minimum plant tillers, lowest leaf water content, leaf area index (LAI), photosynthetic rate (Pn), and transpiration rate (Tr) as well as grain yield. All these parameters, except for leaf water content, Pn after the flowering stage, and grain productivity, were also reduced in the 0.6 ETc treatment than the 1.0 ETc treatment. The differences between the 0.8 ETc and 1.0 ETc treatments were minor in terms of plant height, LAI, spike number, Pn and Tr, but infertile tillers were fewer in the 0.8 ETc treatment. We obtained high yield from the 0.8 ETc treatment, and the 0.6ETc treatment resulted in the highest harvest index with improved WUE than other treatments. Integrating deficit irrigation into SDI can save water in winter wheat production in water-limited regions, which can not only enhance soil water extraction from deep soil layers, but also sustained yield by stimulating crop growth. Therefore, a deficit SDI system would be used to conserve water in water-limited regions.

In the rain-fed areas of northern China, maize ( Zea mays L.) is a main field crop, as it is well adapted to high temperatures and bright sunshine. However, low and variable rainfall and high evapotranspiration rates are common in water-limited environments during the growing season, and often mismatched rainfall events with the critical growth stages, making yield unstable. In this study, the performance of a furrow-planting and straw-mulching system was compared with the conventional flat-planting system in a double-crop culture of winter wheat ( Triticum aestivum L.) and summer maize for two consecutive years (2005–2006 and 2006–2007). The four tested treatments were: conventional flat planting (F), furrow planting between ridges (B), flat planting with wheat straw-mulching (FS), and furrow planting between ridges with wheat-straw mulch (BS). Soil water content and leaf area index (LAI) were measured throughout the growing season each year, and grain yield and precipitation-use efficiency (PUE Y ) were determined. On average, ridge tillage combined with furrow planting increased maize yield by 430 kg ha −1 (7.3%) and PUE Y by 10.7% (1.5 kg ha −1 mm −1 ), compared with the conventional flat planting; furrow planting coupled with straw mulching increased yield by an additional 16.9% and PUE Y by 19.4%, respectively. From jointing to maturity, LAI values of BS were significantly higher than those of F-system (55.6% vs. 26.1% in 2006 and 81.4% vs. 21.7% in 2007). Our data suggest that maize production adopted by furrow planting with straw-covered ridges performed best under seasonal average rainfall below 480 mm, which was associated with better synchronization of seasonal soil water supply and crop needs, leading to improved maize yield and PUE Y .