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Well-facilitied capital farmland construction is an important measure to enhance the ability to ensure food security and accelerate new-style the modernization agriculture. Hyperspectral remote sensing can be provide data basis and technical support for realization the construction of well-facilitied capital farmland，to provide a reference for exploring the optimization of well-facilitied capital farmland construction area. Taking Xinzheng City of main grain producing areas in Henan province as the research object, using field sampling and indoor hyperspectral spectroscopy (350~2500 nm) combined, the spectral transformations such as Continuum removal（ CR） are carried out after the Savitzky-Golay（ SG） convolution smoothing, the best hyperspectral bands as the common index of the soil properties were selected by the correlation analysis and Fuzzy clustering maximum tree，focused on 405~431nm、781nm~831nm、1044~1087nm、1251~1410nm、1836~1898nm、2080nm~2201nm、2324~2395nm. The hyperspectral inversion model had been built by Panel date model of fixed effect variable coefficient based on the ordinary least squares estimation method ( OLS), that is about the panel data of PH、SOM、AN、AP、AK、Fe、Cr、Cd、Zn、Cu、Pb of 116 samples in Xinzheng City. The results showed that: The Panel date model significantly overall, the goodness of fit is higher (in the model, =0.9991， F = 2195.67）. The result of precision test indicates that models performed well in modeling and predicting with a good ability of quantificational prediction, with RPD values were greater than 2.5.

The upper and lower limits of soil water content (SWC) determine the quota and time of regulated deficit irrigation (RDI). The drought resistance of plant varies with growth stages. Therefore, it is very difficult to determine the appropriate upper and lower limits of soil water under different growth stages. This study was first conducted to quantify the non-hydraulic root-sourced signals (nHRS), hydraulic root-sourced signals (HRS) and photosynthetic rate (PN) characteristics of winter wheat in progressively drying soil. Based on the characteristics of root-sourced signals and PN in plant, 3 water control modes were designed: CK (full irrigation, SWC when nHRS occurs was used as the lower limit of irrigation), W1 (SWCs when nHRS occurs and PN decreases significantly were used as the upper and lower limits of irrigation, respectively) and W2 (SWCs when PN decreases significantly and HRS occurs were used as the upper and lower limits of irrigation, respectively). The results showed that W1 and W2 both lowered plant height and leaf area of wheat. W1 had similar PN to CK, but W2 had significantly lower PN compared with CK. W1 and W2 lowered transpiration rates (Tr) and increased leaf instantaneous water use efficiency (WUEleaf) of plant compared with CK. After flowering, W1 lowered root respiration rate and increased accumulated dry matter after flowering (ADM) and pre-flowering dry matter remobilization (DMR) of wheat, and W2 had lower ADM compared to CK. At maturity, W1 had similar yield and higher harvest index compared to CK, but W2 reduced them. W1 significantly reduced irrigation water and improved WUE compared with W2 and CK. In conclusion, controlling suitable soil moisture (W1) based on root-sourced signal characteristics of plant helps to regulate the consumption and distribution of water and photosynthate, thus increasing water use efficiency (WUE) and irrigation water use efficiency (IWUE) of winter wheat.

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.

We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K (NPK) fertilizer was taken as the control (CK) and three organic fertilization treatments were used: NPK fertilizer+pig manure (T1), NPK fertilizer+straw return (T2), NPK fertilizer+pig manure+straw return (T3). The results showed that all three organic fertilization treatments (T1, T2 and T3) significantly increased both soil total N (STN) and soil organic carbon (SOC) from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease (sucrase) and the soil respiration rate (SRS) for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN), the SMBC/SMBN ratio and the microbial quotient (qMB). The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation (CV) of wheat yield and increased the sustainable yield index (SYI). Wheat grain yield was significantly positively correlated with each of the soil microbial properties (P

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.

A field micro-plot experiment was conducted to study the effect of early-stage regulated deficit irrigation (RDI) on the stress tolerance of winter wheat in the late growth stage. Plants were subjected to two RDI treatments: proper water deficits (45-55% field water capacity) were imposed during tillering—the beginning of the spring growth stage (T1) and during the beginning of spring growth to the end of the stem elongation stage (T2). The control plants (CK) were maintained with an adequate water supply until anthesis. The results showed that T1 and T2 shortened the length of the first and second internodes, and increased their weight per unit length, and thereby enhanced stem lodging resistance. Although post-anthesis drought and waterlogging lowered leaf photosynthetic rate and root respiration rate, the two RDI treatments improved significantly compared to the control. The two RDI treatments had no significant effects on grain yield under post-anthesis well-watered conditions but increased grain yield and yield stability of wheat under post-anthesis water stress. In addition, T1 and T2 significantly reduced water consumption and increased water productivity (WP) of wheat compared to the control. In summary, this study shows that appropriate RDI at early growth stages increased grain yield and yield stability through improving population characteristics, root respiration and photosynthesis of plants under post-anthesis water stress conditions. Copyright © 2016 John Wiley & Sons, Ltd.

The annual double-cropping system of winter wheat-summer maize on the North China Plain has caused severe land degradation, particularly soil infertility due to the biannual tillage and straw removal. Two field experiments were conducted from 2012 to 2014. The in situ incubation of wheat and maize straw was measured under four management practices: (i) straw incorporated with application of chemical fertilizer (SF); (ii) straw incorporated with chemical fertilizer and manure (SFM); (iii) straw incorporated with chemical fertilizer and straw-decomposition inoculants (SFD); and (iv) only straw incorporated (CK). Our results showed that SFM and SFD significantly increased the decomposable fraction of straw mass from 64% to 66% in wheat, and 64%–65% in maize straw, as compared to 60% and 53% in wheat and maize respectively, in CKs. SFM and SFD released 77%–78% N and 84%–85% P in wheat straw, while 65%–71% N and 76%–77% P in maize straw in the following crop growing season. A significant increase in straw decomposition and nutrient release induced higher soil urease, phosphatase and invertase activities in SFM and SFD than SF and CK, which resulted higher available N and P in SFM and SFD. Thus, crop yield in the SFM and SFD treatments increased significantly up-to 18–53%. Application of straw incorporated with chemical fertilizer and manure, and their decomposition inoculant is recommended with the advantages of maintaining soil fertility and improving crop production.

Regulated deficit irrigation (RDI) is important water-saving technique. Although some positive effects of RDI have been confirmed in earlier results, more knowledge is still need on how RDI can affect grain growth and drought ability of crops. A micro-plot field experiment was conducted under a movable transparent rain-shelter from October 2011 to June 2012. Three RDI treatments designed to subject the plants to soil water deficit at different stages: tillering-the beginning of the spring-growth stage (RS1), the beginning of the spring-growth to the end of stem elongation stage (RS2), and booting-heading stage (RS3). The results showed that RDI treatments improved the non-hydraulic root-sourced signal (nHRS) sensitivity and photosynthetic capacity of winter wheat. The soil water content (SWC) of RS1, RS2 and RS3 treatments when the nHRS was triggered and net photosynthetic rate (PN) declined significantly was significantly lower than the control during progressive soil drying. After flowering stage, RS1 and RS2 treatments had significantly lower post-flowering accumulated dry matter (ADM), and but increased pre-flowering dry matter remobilization (DMR) in well-watered group, and both significantly increased DMR and ADM of wheat in dried group compared to the control. RS1 and RS2 had no significant effect on grain yield in well-watered group, but significantly increased grain yields in dried group. In addition, RS1 and RS2 also increased water use efficiency (WUE) and yield stability of winter wheat compared to the control. Above all, the results of this study showed that RS1 and RS2 treatments significantly increased drought resistance ability of winter wheat through improving the nHRS sensitivity of plants during progressive soil drying, and increased grain yield through increasing both current photosynthesis and the remobilization of pre-anthesis carbon reserves.

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 .

A pot and a field experiment were conducted to assess the effects of root/shoot ratio (R/S) on the water use efficiency (WUE) and grain yield of winter wheat. The R/S was regulated by pruning the roots during the stem elongation stage, resulting in reduced root systems of the plants. At the heading stage, the root dry weight of root-pruned plants was less than that of intact-root plants, but their R/S was similar to that of intact-root plants under both experimental conditions. After tiller pruning, the R/S of root-pruned plants was significantly lower than that of intact-root plants (p < 0.05). Root pruning reduced the rate of leaf transpiration and lowered the number of tillers per plant (p < 0.05) during the vegetative stage. As a result, root-pruned wheat showed reduced water use when compared to intact-root plants before heading (p < 0.05). At anthesis, there was no significant difference in transpiration between plants with intact roots and those with pruned roots in the pots. However, under field conditions, transpiration of root-pruned plants was significantly higher than that of intact-root plants at anthesis. Additionally, at anthesis root-pruned plants had a higher rate of leaf photosynthesis and lower rate of root respiration, which resulted in a significantly higher grain yield at maturity when compared to plants with intact roots. Under both experimental conditions, there were no significant differences in shoot dry weight per plant between root-pruned and intact-root plants grown in monoculture. When root-pruned plants were grown with intact-root plants, the root-pruned wheat was less productive and had a lower relative shoot dry weight (0.78 and 0.86, respectively) than the intact-root plants (1.24 and 1.16, respectively). These results suggest that plants with pruned roots had a lower ability to compete and to acquire and use the same resources in the mixture when compared with intact-root plants. Root pruning improved the WUE of winter wheat under both experimental conditions. This suggests that appropriate management for the root system/tillers in wheat crops can be used to increase grain yield and water use efficiency. Specifically, lowering the R/S improved the grain yield and WUE of winter wheat significantly by lowering its competitive ability and improving root efficiency. Therefore, drought-resistance breeding to improve the grain yield and WUE, at least for wheat, should be made by targeted selection of less competitive progeny with a small R/S for cultivation in arid and semiarid areas.

A pot experiment was conducted to study the effects of root pruning at the stem elongation stage on the growth and water use efficiency (WUE) of winter wheat (Triticum aestivum). The results showed that stomatal conductance (g) and transpiration (E) of wheat were very sensitive to root pruning. After root pruning, they declined rapidly and but returned to pre-pruning values 15 days after treatment. Under well-watered conditions, there was no significant difference in leaf water potential (ψleaf) between root pruned and control plants after root pruning. Under moderate drought stress, ψleaf of root pruned plants declined significantly compared to the control 3 days after root pruning. After 15 days, ψleaf of root pruned plants was similar to the controls. Under different soil moisture levels, net assimilation rate (A) of root pruned plants was lower than controls 3–7 days after root pruning, but was similar to the controls 15 days after pruning. At anthesis (50 days after root pruning), root pruned plants showed significantly higher A compared with the control. Leaf area per tiller and tiller number of root pruning plants was significant lower than the control at booting stage, which showed that root pruning restrained the growth of plants in the early growing stage, but leaf area per stem, of root pruned plants, was similar to the control at anthesis. Under both soil moisture levels, there was no significant difference in grain yield between root pruned and the control plants in the monoculture. In mixture with the control plants, the root pruned plants was less productive and had a lower relative yield (0.92 and 0.78, respectively) compared with the control (1.13 and 1.19, respectively), which suggested that the pruned plants lost some of its competing ability and showed a lower ability to acquire and use the same resources in the mixture compared with the control plant. Over the whole growing cycle, root pruning reduced water consumption (by 10% under well-watered conditions and 16% under moderate drought stress) of wheat significantly compared to the control (P < 0.05), and but there was no significant difference in grain yield between root pruned and control plants. Therefore root pruned wheat had a higher WUE with respect to grain yield compared with the controls. In conclusion, lowering water consumption by root pruning in the early growing stage is an effective way to improve water use efficiency in arid and semi arid areas.

This study was conducted to assess the effect of root system size and vertical distribution on competitive ability and water use efficiency (WUE) by root pruning at the stem elongation stage. The field experiments were carried out from 2004 to 2005 and 2005 to 2006 in the Loess Plateau regions, China. Root pruning succeeded in reducing root dry weight in the upper soil (0–20 cm soil layer), resulting in diminished total root weight in root pruned wheat (p

A pot culture experiment was conducted to study the effects of postponing nitrogen (N) application on photosynthetic characteristics and grain yield of winter wheat subjected to water stress after heading stage. Equal in the total N rate in winter wheat growth season, N application was split before sowing, and/or at jointing and /or at anthesis at the ratio of 10:0:0 (N1), 6:4:0 (N2) and 4:3:3 (N3), combined with unfavorable water condition (either waterlogged or drought) with the sufficient water condition as control. The results showed that, under each of the water condition, both N2 and N3 treatments significantly improved the leaf photosynthetic rate and the SPAD value of flag leaf compared with N1 treatment during grain filling stage, and also the crop ear number, grain number per spike and above-ground biomass were increased. Although postponing nitrogen application increased water consumption, both grain yield and water use efficiency were increased. Compared with sufficient water supply, drought stress and waterlogging stress significantly reduced the photosynthetic rate of flag leaves at anthesis and grain filling stages, ear number, 1000-grain mass and yield under all of the N application patterns. The decline of photosynthetic rate under either drought stress or waterlogging stress was much less in N2 and N3 than in N1 treatments, just the same as the grain yield. The results indicated that postponing nitrogen application could regulate winter wheat yield as well as its components to alleviate the damages, caused by unfavorable water stress by increasing flag leaf SPAD and maintaining flag leaf photosynthetic rate after anthesis, and promoting above-ground dry matter accumulation.

In China, coal-mining industries are mainly located in the water shortage areas including arid or semiarid areas. Mine wastewater is used for irrigation of agricultural land in these areas. However, few studies have been conducted to address ecological and food safety risks caused by mine wastewater irrigation. In this research, a pot experiment was performed to examine the effects of mine wastewater irrigation on soil enzymes, physiological properties of wheat and potential risks of heavy metal contamination to wheat crop. Plants were subjected to three mine wastewater irrigation treatments: leacheate of coal gangue (T1), coal-washing wastewater (T2) and precipitated coal-washing wastewater (T3). Plants irrigated with well water were taken as the control (CK). The results showed that mine wastewater irrigation caused adverse effects on soil enzymes, physiological properties and grain yield of winter wheat. At anthesis, T1, T2 and T3 treatments significantly reduced the activities of soil enzymes (urease, sucrase and catalase), root activity and net photosynthetic rate of wheat compared to CK. At maturity, grain yield was decreased by 17.8%, 15.4% and 9.8% by T1, T2 and T3, respectively, as compared to that of CK. Importantly, mine wastewater irrigation resulted in accumulation of heavy metals (Cr, Pb, Cu and Zn) in wheat grain. Contents of these heavy metals in grains of winter wheat subjected to mine wastewater irrigation were significantly higher than those in CK. The comprehensive contamination indexes of wheat grain in T1, T2 and T3 all reached high pollution level. Our results showed that mine wastewater irrigation significantly increased the pollution risk of heavy metals, thus unsuitable for crop irrigation.

A pot experiment was conducted to study the effects of irrigation with mine wastewater on the physiological characters and heavy metals accumulation of winter wheat. Three treatments were installed, i. e., irrigation with coal-washing wastewater (T1), irrigation with coal-washing wastewater after its precipitation (T2), and irrigation with coal gangue leacheate (T3), taking the well water irrigation as the control (CK). The plants were irrigated with mine wastewater after the turning green stage. Irrigation with mine wastewater had negative effects on the winter wheat growth and grain yield. At anthesis stage, the leaf area, dry mass per stem, root activity, and net photosynthetic rate of winter wheat in treatments T1, T2, and T3 were significantly lower than those in CK (P0.05), the plant height and leaf chlorophyll content in T3 decreased significantly (P0.05), and the grain yield in T1, T2 and T3 was decreased by 15.4%, 9.8%, and 17.8%, respectively. In addition, the heavy metals (Cr, Pb, Cu and Zn) contents in the grain of winter wheat under mine wastewater irrigation were significantly higher than those in CK, suggesting that the irrigation with mine wastewater could result in the heavy metals accumulation in wheat grain.

In a pot experiment, different measures were conducted to improve coal waste rock contaminated soil and explored growth, photosynthesis and yield traits of soybean under different improvement measures. Three improvement measures were employed: A (filled with fly ash), B (filled with dairy manure), C (filled with fly ash and dairy manure), the control (CK) is mixed soil (topsoil and coal waste rock). The results showed that 3 improvement measures improved plant height, leaf area and number of root nodules of soybean. There was the highest plant height, leaf area and number of root nodules in C treatment followed by B, A and then CK at different growing stages. At flowering and Seed-filling stage, chlorophyll content and photosynthesis rate of soybean under 3 improvement measures were higher than those of the control (CK). There was the highest Chlorophyll content and photosynthesis rate in C treatment followed by B, and A. 3 improvement measures also improved pod number per plant, seed weight per plant and 100 grain weight of soybean, which resulted in increased yield compared to the control (CK), in which C treatment increased by 68.77%, followed by B and A by 41.160%, 30.87%, respectively.

Taking two winter wheat (Triticum aestivum L.) cultivars Changwu 135 and Pingliang 40 commonly cultivated in the semi-arid area on Loess Plateau as test materials, and by the method of ecological replacement, a 2-year field experiment was conducted to study the effects of mono- and mixed culture on the grain yield and water use efficiency of the cultivars. The results showed that under mono-culture, Pingliang 40 had a much higher unit area root biomass (367.60 g x m(-2)) than Changwu 135 (297.31 g x m(-2)), and a more uniform root distribution (i.e., a better root type for water absorption), but its grain yield and water use efficiency were lower than Changwu 135. Under mixed culture, the population root biomass of Pingliang 40 and Changwu 135 was 13.36 g * m(-2) and 8.50 g x m(-2) higher than that under mono-culture, respectively, suggesting that mixed population could absorb the water in deeper soil layers, and had higher total unit area biomass, which in turn increased the water use efficiency. Comparing with Pingliang 40, Changwu 135 allocated more dry matter to its productive organ, leading to its higher grain yield, harvest index, and water use efficiency.