Winter Wheat Grain Yield Research Articles

Impact of Different Irrigation Managements on Soil Water Consumption, Grain Yield, Seed Protein, Phosphorus and Potassium of Winter Wheat

Abstract To evaluate soil water consumption, changes in quantity and quality of winter wheat seed and forage under different irrigation treatments, an experiment was conducted in Beijing, China, in the 2012-2013. Irrigation treatments were (I1): irrigation before sowing, (I2): irrigation before sowing + before freezing; (I3): irrigation before sowing + before freezing + irrigation in the beginning of erecting stage + irrigation at flowering stage; (I4): irrigation before sowing + irrigation before freezing + irrigation at the booting stage + irrigation at flowering stage. The laid out of experiment was randomized complete block design, repeated six times. The effect of irrigation on total biological yield, grain yield and harvest index is significant. The highest mean soil water consumption in Oct., Nov., Dec., Jan., Feb., Mar., Apr. and May was obtained for lysimeter 10 (I2), lysimeter 10 (I2), lysimeter 6 (I2), lysimeter 10 (I2), lysimeter 10 (I2), lysimeter 10 (I2), lysimeter 11 (I3), and lysimeter 10 (I2), respectively. The results from the study indicate that irrigation winter wheat throughout the booting stage and flowering stage increased grain yield, harvest index, potassium percentage, ash percentage of forage wheat at flowering stage, seed and forage protein percentage. Evapotranspiration trends increased steadily, especially in last three months, in which the lysimeter fields were covered by winter wheat completely.

Association mapping reveals loci associated with multiple traits that affect grain yield and adaptation in soft winter wheat

Genome-wide association studies (GWAS) are useful to facilitate crop improvement via enhanced knowledge of marker-trait associations (MTA). A GWAS for grain yield (GY), yield components, and agronomic traits was conducted using a diverse panel of 239 soft red winter wheat (Triticum aestivum) genotypes evaluated across two growing seasons and eight site-years. Analysis of variance showed significant environment, genotype, and genotype-by-environment effects for GY and yield components. Narrow sense heritability of GY (h 2 = 0.48) was moderate compared to other traits including plant height (h 2 = 0.81) and kernel weight (h 2 = 0.77). There were 112 significant MTA (p < 0.0005) detected for eight measured traits using compressed mixed linear models and 5715 single nucleotide polymorphism markers. MTA for GY and agronomic traits coincided with previously reported QTL for winter and spring wheat. Highly significant MTA for GY showed an overall negative allelic effect for the minor allele, indicating selection against these alleles by breeders. Markers associated with multiple traits observed on chromosomes 1A, 2D, 3B, and 4B with positive minor effects serve as potential targets for marker assisted breeding to select for improvement of GY and related traits. Following marker validation, these multi-trait loci have the potential to be utilized for MAS to improve GY and adaptation of soft red winter wheat.

Late‐season photosynthetic rate and senescence were associated with grain yield in winter wheat of diverse origins

AbstractThere is a lack of studies that have investigated grain yield, its components and photosynthesis in late stages of wheat growth, giving us insufficient understanding of how these factors interact to contribute to yield during this period. As a result, three field experiments were carried out examining 20 winter wheat genotypes of diverse origins under irrigated, terminal drought and dryland conditions in the southern Idaho. Our objective was to evaluate the interaction between post‐anthesis physiological traits, especially leaf‐level photosynthetic capacity, senescence and yield components on grain yield in different moisture regimes. Genotype differences were found in leaf‐level photosynthesis and senescence, canopy temperature depression, grain yield and yield components in each water regime. Grain yield was closely associated with traits related to grain numbers. In all three moisture regimes, positive correlations were observed between grain yield and photosynthesis that were dependent on the timing or physiological growth stage of the photosynthetic measurement: highly significant correlations were found in the mid‐ and late grain filling stages, but no correlations at anthesis. Consistent with these findings, flag leaf senescence at the late grain filling stage was negatively correlated with grain yield and photosynthetic rate (under terminal drought and dryland conditions). These findings provided evidence that grain yield was sink‐limited until the final stages of growth, at which time sustained photosynthesis and delayed senescence were critical in filling grain. Because the trends were consistent in moisture sufficient and deficient conditions, the results suggest that late‐season photosynthesis and delayed leaf senescence are driven by the size of the reproductive carbon sink, which was largely governed by factors affecting grain numbers.

Straw return and appropriate tillage method improve grain yield and nitrogen efficiency of winter wheat

AbstractStraw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing and rotary tillage practices are widespread in the region, only few studies have focused on rotation tillage. To determine the effects of maize straw return on the nitrogen (N) efficiency and grain yield of winter wheat (Triticum aestivum L.), we conducted experiments in this region for 3 years. Five treatments were tested: (i) rotary tillage without straw return (RT); (ii) deep plowing tillage without straw return (DT); (iii) rotary tillage with total straw return (RS); (iv) deep plowing tillage with total straw return (DS); (v) rotary tillage of 2 years and deep plowing tillage in the 3rd year with total straw return (TS). Treatments with straw return increased kernels no. ear−1, thousand-kernel weight (TKW), grain yields, ratio of dry matter accumulation post-anthesis, and nitrogen (N) efficiency whereas reduced the ears no. ha−1 in the 2011–2012 and 2012–2013 growing seasons. Compared with the rotary tillage, deep plowing tillage significantly increased the grain yield, yield components, total dry matter accumulation, and N efficiency in 2013–2014. RS had significantly higher straw N distribution, soil inorganic nitrogen content, and soil enzymes activities in the 0–10 cm soil layer compared with the DS and TS. However, significantly lower values were observed in the 10–20 and 20–30 cm soil layers. TS obtained approximately equal grain yield as DS, and it also reduced the resource costs. Therefore, we conclude that TS is the most economical method for increasing grain yield and N efficiency of winter wheat in Huang-Huai-Hai Plain.

Spatial and temporal nitrogen applications for winter wheat in a loamy soil in south-eastern China

Split application of nitrogen (N), applied by broadcasting, is both time consuming and inconvenient; yet it is widely practised for wheat. Simplified N fertilization is necessary for wheat in south-eastern China. One-time band application was compared with split application using three doses of N (150, 195, and 240 kg ha−1) in 2014/2015 and 2015/2016. Grain yield and N-use efficiency of winter wheat were determined over two consecutive seasons. A corresponding micro-plot trial using 15N-labelled urea was conducted only in 2015/2016 to measure the fate of urea-15N. The two methods showed no difference in grain yield, except at 240 kg ha−1 of N in 2014/2015. The average grain N concentration (18.2 g kg−1) was slightly lower in band application than that in broadcast application (19.2 g kg−1), but there was no significant difference (P > 0.05). In 2014/2015, N apparent recovery efficiency ranged from 33.1 to 49.9%; N agronomic efficiency, from 8.9 to 38.9 kg kg−1; and N partial factor productivity, from 23.6 to 38.4 kg kg−1. In 2015/2016, the corresponding values were 29.4–38.6%, 13.5–38.6, and 24.3–33.9 kg kg−1. In the micro-plot trial, compared to split application, fertilizer N recovery in winter wheat in one-time band application was lower by 26.5% and increased the unaccounted-N loss by 21.7%. Thus, considering environmental impacts, one-time band application of N at sowing is not a suitable alternative to broadcast application in split doses for winter wheat in the loamy soils of south-eastern China.

Effect of Nitrogen and Sulphur Fertilization on Chlorophyll Content in Winter Wheat

Abstract Nitrogen management strategy in plant growth period based on chlorophyll content evaluation in plant can improve nitrogen usage efficiency and reduce environmental contamination. This study is aimed to determine the impact of different nitrogen and sulphur fertilizer rates on dynamics of chlorophyll content in winter wheat during vegetative growth and to determine the relationship between nitrogen and chlorophyll content and grain yield of winter wheat. Field trial involving a winter wheat (Triticum aestivum L.) variety ‘Kranich’ was conducted at the LUA Research and Study Farm Vecauce during a three-year period (2012-2015). The treatments were 0, 85, 153, 175+S21, 175 (in 2015), 187 N kg ha−1 and different nitrogen norms according to chlorophyll meter Yara N-tester (Konica Minolta Ltd.) data: 180, 150, 205 N kg ha−1 depending on the year. The results of the trial show that the maximum chlorophyll content in different plant parts was observed at the end of flowering stage. The chlorophyll content depended on the level of mineral fertilisation. The highest chlorophyll content in leaves, stems and ears was obtained by using additional sulphur in two trial years. Usage of chlorophyll meter Yara N-tester obtained the highest chlorophyll content in all analyzed plant parts in one trial year. Chlorophyll content was significantly dependant on plant growth stage in stems in all trial years, in leaves in two trial years, and in ears in one year. Nitrogen fertilization significantly affected chlorophyll content in leaves and stems in one trial year. Close positive correlation was observed between grain yield and wheat plant chlorophyll content and average nitrogen concentration at the end of flowering stage in all three trial years.

Physiological mechanisms contributing to increased water-use efficiency in winter wheat under organic fertilization.

Improving the efficiency of resource utilization has received increasing research attention in recent years. In this study, we explored the potential physiological mechanisms underlying improved grain yield and water-use efficiency of winter wheat (Triticum aestivum L.) following organic fertilizer application. Two wheat cultivars, ChangHan58 (CH58) and XiNong9871 (XN9871), were grown under the same nitrogen (N) fertilizer rate (urea-N, CK; and manure plus urea-N, M) and under two watering regimes (WW, well-watered; and WS, water stress) imposed after anthesis. The M fertilizer treatment had a higher Pn and lower gs and Tr than CK under both water conditions, in particular, it significantly increased WRC and Ψw, and decreased EWLR and MDA under WS. Also, the M treatment increased post-anthesis N uptake by 81.4 and 16.4% under WS and WW, thus increasing post-anthesis photosynthetic capacity and delaying leaf senescence. Consequently, the M treatment increased post-anthesis DM accumulation under WS and WW by 51.5 and 29.6%, WUEB by 44.5 and 50.9%, grain number per plant by 11.5 and 12.2% and 1000-grain weight by 7.3 and 3.6%, respectively, compared with CK. The grain yield under M treatment increased by 23 and 15%, and water use efficiency (WUEg) by 25 and 23%, respectively. The increased WUE under organic fertilizer treatment was due to elevated photosynthesis and decreased Tr and gs. Our results suggest that the organic fertilizer treatment enabled plants to use water more efficiently under drought stress.

Delayed sowing can increase lodging resistance while maintaining grain yield and nitrogen use efficiency in winter wheat

Lodging resistance of winter wheat (Triticum aestivum L.) can be increased by late sowing. However, whether grain yield and nitrogen use efficiency (NUE) can be maintained with delayed sowing remains unknown. During the 2013–2014 and 2014–2015 growing seasons, two winter wheat cultivars were sown on three dates (early sowing on October 1, normal sowing on October 8, and late sowing on October 15) to investigate the responses of lodging resistance, grain yield, and NUE to sowing date. No significant differences in lodging resistance, grain yield, or NUE between early and normal sowing were observed. Averaging over the two cultivars and years, postponing the sowing date significantly increased lodging resistance by 53.6% and 49.6% compared with that following early and normal sowing, respectively. Lodging resistance was improved mainly through a reduction in the culm height at the center of gravity and an increase in the tensile strength of the base internode. Late sowing resulted in similar grain yield as well as kernel weight and number of kernels per square meter, compared to early and normal sowing. Averaging over the two cultivars and years, delayed sowing resulted in a reduction in nitrogen uptake efficiency (UPE) by 11.0% and 9.9% compared to early and normal sowing, respectively, owing to reduced root length density and dry matter accumulation before anthesis. An average increase in nitrogen utilization efficiency (UTE) of 12.9% and 11.2% compared to early and normal sowing, respectively, was observed with late sowing owing to a reduction in the grain nitrogen concentration. The increase in UTE offset the reduction in UPE, resulting in equal NUEs among all sowing dates. Thus, sowing later than normal could increase lodging resistance while maintaining grain yield and NUE.

Yield, water productivity and economic return of dryland wheat in the Loess Plateau in response to conservation tillage practices

SUMMARYWinter wheat (Triticum aestivum L.) production on the Loess Plateau in China has been threatened by water scarcity and climate change during the last decade. Sustainable crop production in this region requires managerial practices that can provide high yield and high water productivity (WP). A 7-year (2001–2008) study at the Loess Plateau Research Station of Lanzhou University investigated the effects of various conservation tillage practices on grain yield, soil water content (SWC), WP and economic return of winter wheat production. Tillage treatments included: conventional tillage (T), conventional tillage followed by stubble retention (TS), no-till (NT) and no-till followed by stubble retention (NTS). Over the entire experimental period, grain yield and WP of winter wheat ranged from 1279 to 4894 kg/ha and 0·32 to 2·41 kg/m3, respectively. Both were significantly affected by tillage treatment and year, while SWC was only affected by year. Grain yield and WP in TS was increased by 4·9, 12·1, 0·9% and 13·7, 20·4 and 3·9% compared with NTS, NT and T, respectively, over seven growing seasons. Additionally, a multiple linear regression analysis indicated that grain yield is mainly limited by SWC during planting. Despite its lower grain yield, the NTS treatment increased economic benefit by US$ 328, US$ 23 and US$ 87/ha compared with TS, NT and T, respectively. Therefore, it is suggested that increasing soil water storage at wheat sowing time and encouraging the use of NTS could improve economic returns in this region.

Effects of Nanochitin on the Enhancement of the Grain Yield and Quality of Winter Wheat

This study investigated the effects of different rates of nanochitin in soil on the grain yield and quality of winter wheat. Nanochitin obtained by acidic hydrolysis of shrimp chitin was a rod-like whisker possessing a hydrodynamic diameter of 143 nm and ζ potential of 55.7 mV. Two varieties of winter wheat, multi-spike wheat (MSW) and large spike wheat (LSW), were treated with the nanochitin suspension in outside pot experiments. The results showed that 0.006 g kg-1 of nanochitin in soil could significantly enhance the yield by 23.0% for MSW and 33.4% for LSW, with significant increases of net photosynthesis rate, stomatal conductance, intercellular CO2 concentrations, and transpiration rate in flag leaf at the grain filling stage. Grain protein, iron, and zinc contents in wheat treated with nanochitin were also increased by 5.0, 10.3, and 22.1% for MSW and 33.4, 32.0, and 27.0% for LSW, respectively. This indicated that utilization of nanochitin has a great potential in future agriculture sustainability and crop production.

Effect of irrigation and nitrogen application on grain amino acid composition and protein quality in winter wheat.

Water management and nitrogen application are critical factors in wheat grain yield and protein quality. This study aimed to evaluate the effect of irrigation and nitrogen application on the grain yield, protein content and amino acid composition of winter wheat. Field experiments were conducted in a split-plot design with three replications in high-yielding land on the North China Plain in 2012/2013, 2013/2014 and 2014/2015. Three irrigation treatments were examined in main plots: no irrigation, irrigation at jointing, and irrigation at jointing plus anthesis, while subplots were assigned to nitrogen treatment at four different rates: 0, 180, 240, 300 kg N ha-1, respectively. The results indicated that irrigation at jointing and at jointing plus anthesis improved grain yield by an average of 12.79 and 18.65% across three cropping seasons, respectively, compared with no irrigation. However, different irrigation treatments had no significant effect on grain protein content in any cropping season. Compared with no N treatment, 180, 240, and 300 kg N ha-1 N application significantly increased grain yield, by 58.66, 61.26 and 63.42% respectively, averaged over three cropping seasons. Grain protein and the total, essential and non-essential amino acid content significantly increased with increasing nitrogen application. Irrigation significantly improved the essential amino acid index (EAAI) and protein-digestibility-corrected amino acid score (PDCAAS) compared with no irrigation; however, N application decreased them by an average of 7.68 and 11.18% across three cropping seasons, respectively. EAAI and PDCAAS were positively correlated, however, they were highly negatively correlated with yield and grain protein content.

Tailoring NPK fertilizer application to precipitation for dryland winter wheat in the Loess Plateau

Over-fertilization is economically and environmentally undesirable, and under-fertilization contributes to yield gaps. In dryland cropping systems, where precipitation is a major source of variation in yield, matching fertilizer to precipitation is critical. The aim of this study was to outline and test a method to match nitrogen (N), phosphorus (P), and potassium (K) fertilizer rate to precipitation for dryland winter wheat in the Loess Plateau of China. Based on field experiments at 52 sites from 2009 to 2013, the grain yield of winter wheat was found to increase quadratically with the precipitation in two periods: summer fallow, and summer fallow until jointing stage. The shoot N, P, and K nutrient uptake were linearly correlated with grain yield. Basal fertilizer requirement was calculated from target grain yield estimated as a function of fallow precipitation. The need for topdressing was determined by re-estimating target grain yield as a function of precipitation during summer fallow until jointing stage. Validation of this method using an additional dataset from long term studies in the same area suggested that adjusting fertilizer rates to summer fallow and summer fallow until jointing precipitation could correct the over application for N and P fertilizer, and deficient application for K fertilizer in the Loess Plateau.

Effect of Localities and organic Fertilizers on Yield in Conditions of Organic Farming

Nitrogen fertilization cannot be used by actual needs of plants during vegetation in organic farming. The proper crop rotation and harmonic nutrition are necessary for good and quality products. The methods of treatment are mainly realized by cultivation of green manure crop and fertilizing by organic fertilizers. The aim of the long-term experiment was to evaluate the effect of different localities and different organic fertilizers on crop yield in organic farming. Variants of fertilization included in the experiment are: 1. Unfertilized control, 2. Green manure, 3. Green manure + renewable external sources, 4. Green manure + renewable external sources + auxiliary substances, 5. Green manure + farm fertilizers, 6. Green manure + farm fertilizers + auxiliary substances. The experiment started by sowing of winter wheat so green manure crop was not grown in the first experimental year. The highest yield of winter wheat grain coming from the first year of the experiment was observed on the variant with renewable external sources (digestate). Average grain yield on this variant was about 7.12 t/ha (up to 0.74 t/ha increased than the unfertilized control). Average yield of potatoes from the second year of the experiment was the highest after combination with green manure + renewable external sources (compost + digestate) + auxiliary substances. This variant achieved yield about 34.08 t/ha, which is increased by 9.35 t/ha compared to the control variant. Results from this two-year experiment showed that the most suitable combination of fertilization with or without green manure crop is compost + digestate. These results were probably caused by higher content of nitrogen in organic fertilizers (compost + digestate) used in this variant compared to other variants. Statistical difference of achieved yields was observed between each experimental station in both experimental years.

Moderate Drought Stress Affected Root Growth and Grain Yield in Old, Modern and Newly Released Cultivars of Winter Wheat.

To determine root growth and grain yield of winter wheat (Triticum aestivum L) under moderate drought stress, a nursery experiment and a field trial were conducted with or without water stress using three representative cultivars released in different years: CW134 (old landrace), CH58 (modern cultivar) and CH1 (new release). In the nursery experiment, plants were grown in soil-filled rhizoboxes under moderate drought (MD, 55% of field capacity) or well-watered (WW, 85% of field capacity) conditions. In the field trial, plots were either rainfed (moderate drought stress) or irrigated with 30 mm of water at each of stem elongation, booting and anthesis stages (irrigated). Compared to drought stress, grain yields increased under sufficient water supply in all cultivars, particular the newly released cultivar CH1 with 70% increase in the nursery and 23% in the field. When well-watered (nursery) or irrigated (field), CH1 had the highest grain yields compared to the other two cultivars, but produced similar yield to the modern cultivar (CH58) under water-stressed (nursery) or rainfed (field) conditions. When exposed to drought stress, CW134 had the highest topsoil root dry mass in topsoil but lowest in subsoil among the cultivars at stem elongation, anthesis, and maturity, respectively; while CH1 had the lowest topsoil and highest subsoil root dry mass at respective sampling times. Topsoil root mass and root length density were negatively correlated with grain yield for the two water treatments in nursery experiment. When water was limited, subsoil root mass was positively correlated with thousand kernel weight (TKW). In the field trial, CH1 and CH58 used less water during vegetative growth than CW134, but after anthesis stage, CH1 used more water than the other two cultivars, especially in the soil profile below 100 cm, which was associated with the increased TKW. This study demonstrated that greater root mass and root length density in subsoil layers, with enhanced access to subsoil water after anthesis, contribute to high grain yield when soil water is scarce.

Effect of fungicide combinations for FHB control on disease incidence, grain yield and quality of winter wheat, spring wheat and barley

This study investigates the effects of timing of fungicide applications alone or in combinations on Fusarium head blight (FHB), seed deoxynivalenol (DON) concentrations, dominant leaf diseases, gra...

Effects of long term tillage practices on photosynthetic characteristics and grain yield of wheat

A field experiment was conducted to study the effects of long-term tillage practices on photosynthetic characteristics of flag leaf, dry matter accumulation and its allocation, and grain yield, with a wheat cultivar, Jimai 22, in both 2013-2014 and 2014-2015 growing seasons. Four tillage practices, namely rotary tillage (R), plowing (P), strip rotary tillage and subsoiling at an interval of 2 years (SRS), and rotary tillage and subsoiling at an interval of 2 years (RS), were conducted in field for 9 years since 2007. The results showed that the net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (gs) of flag leaves under SRS treatment were significantly higher than those of other treatments from 21 to 35 days after anthesis. The SRS treatment had higher average photosynthetically active radiation (PAR) capture ratio than RS and P treatments, while the lowest values were found under R treatment during grain-filling stage. Compared with the other treatments, the plants of SRS treatment had the highest accumulation of dry matter at maturity, the highest allocation of dry matter in grains, and the highest contribution ratio of dry matter from vegetative organs to grains after anthesis. The grain yield and water use efficiency of SRS treatment were significantly higher than those of the other treatments, and the water consumption amount of SRS treatment was significantly higher than that of both R and P treatments, with no significant difference from the RS treatment. Under the current experimental condition, it was suggested that SRS would be the most effective tillage practice to increase both grain yield and water use efficiency for winter wheat production.

Effects of tillage practices on photosynthetic performance diurnal variation during filling stage and grain yield of winter wheat

Photosynthesis characteristics of winter wheat under different tillage practices during fil-ling stage are vital for dry matter accumulation, transfer, and yield development. A field experiment, including no-till with residue removal (NT), no-till with residue retention (NTS), rotary tillage with residue removal (RT), rotary tillage with residue retained (RTS), subsoiling with residue removal (DT), subsoiling with residue retained (DTS), plow tillage with residue removal (CT), and plow tillage with residue retained (CTS) was conducted at Wuqiao experimental station of China Agricultural University since October 2008. The diurnal variation of photosynthetic characteristics of flag leaf, photosynthetic response curve, and crop yield under different tillage practices were evaluated during winter wheat filing stage in this study. The results showed thatthe net photosynthetic rate and stomatal conductance of flag leaf both diurnally varied with the bimodal curve, and the net photosynthetic rates were higher under treatments with residue retained than those under with residue removal. Diurnal variation of intercellular carbon dioxide concentration was observed with a "V-shaped wide mouth" bimodal curve under all treatments. Daily transpiration rate exhibited "double peak curve", except for the "single peak curve" under DTS, RTS and RT. The stimulated net photosynthetic rate was increased by 20.0%, 21.7%, 19.7%, 21.5%, 0.8%, 12.1% and 4.2% under NT, DT, RT, CT, CTS, RTS, and CTS, compared with DTS, respectively. Photosynthetic response curves were fitted better under treatments with residue retained than under treatments with residue removal. As for crop grain yields, the highest one was observed under DTS, following by RTS and CTS, and the lowest under CT. Crop grain yield was increased by 10.8%, 1.3%, 2.1%, 5.4%, 11.9%, 12.4%, and 12.6% under DTS, compared with NTS, RTS, CTS, NT, DT, RT, and CT, respectively. Thus, residue retaining under different tillage practices (e.g. NTS and DTS) could mitigate the mid-day depression of photosynthesis, maintain a high photosynthetic rate of winter wheat, and improve the dry matter accumulation and crop production.

Nitrogen uptake, nitrate leaching and root development in winter‐grown wheat and fodder radish

AbstractEarly seeding of winter wheat (Triticum aestivum L.) has been proposed as a means to reduce N leaching as an alternative to growing cover crops like fodder radish (Raphanus sativus L.). The objective of this study was to quantify the effect of winter wheat, seeded early and normally, and of fodder radish on N dynamics and root growth. Field experiments were carried out on a humid temperate sandy loam soil. Aboveground biomass and soil inorganic N were determined in late autumn; N uptake and grain yield of winter wheat were measured at harvest. Nitrate leaching was estimated from soil water samples taken at 1 m depth. Root growth was measured late autumn using the core break and root washing methods. Winter wheat root growth dynamics were followed during the growing season using the minirhizotron method. The 2013–2014 results showed that early seeding of wheat improved autumn growth and N uptake and reduced N leaching during the winter compared with the normal seeding time. Early‐seeded wheat (WWearly) was, however, not as efficient as fodder radish at reducing N leaching. Proper establishment of WWearly was a prerequisite for benefiting from early seeding, as indicated by the 2012–2013 results. Early seeding improved root growth throughout the 2013–2014 growing season compared with normal seeding time, but had no significant effect on crop grain yield. Our results indicate the potential of using early seeding as a tool to limit drought susceptibility and increase nutrient uptake from the subsoil.

Grain yield and water use of winter wheat as affected by water and sulfur supply in the North China Plain

Water shortage has threatened sustainable development of agriculture globally as well as in the North China Plain (NCP). Irrigation, as the most effective way to increase food production in dry land, may not be readily available in the situation of drought. One of the alternatives is to supply plants with enough nutrients so that they can be more sustainable to the water stress. The objective of this study was to explore effects of irrigation and sulphur (S) application on water consumption, dry matter accumulation (DMA), and grain yield of winter wheat in NCP. Three irrigation regimes including no irrigation (rainfed, I0) during the whole growth period, once irrigation only at jointing stage (90 mm, I1), and twice respective irrigation at jointing and anthesis stages (90 mm plus 90 mm, I2), and two levels of S application including 0 (S0) and 60 kg ha−1 (S60) were designed in the field experiment in NCP. Results showed that increasing irrigation times significantly increased mean grain yield of wheat by 12.5-23.7% and nitrogen partial factor productivity (NPFP) by 21.2-45.0% in two wheat seasons, but markedly decreased crop water use efficiency (YWUE). Furthermore, S supply 60 kg ha−1 significantly increased mean grain yield, YWUE, IWUE and NPFP by 5.6, 6.1, 23.2, and 5.6% (across two wheat seasons), respectively. However, we also found that role of soil moisture prior to S application was one of important greater factors on improving the absorption and utilization of storage water and nutrients of soil. Thus, water supply is still the most important factor to restrict the growth of wheat in the present case of NCP, supplying 60 kg ha−1 S with once irrigation 90 mm at the jointing stage is a relatively appropriate recommended combination to improve grain yield and WUE of wheat when saving water resources is be considered in irrigated wheat farmlands of NCP.

The long-term effect of climate change on productivity of winter wheat in Denmark: a scenario analysis using three crop models

SUMMARYThe response of grain yield, grain nitrogen (N), phenological development and evapotranspiration of winter wheat to climate change was analysed over an 80-year period based on climate change predictions of four regional circulation models (RCMs) under the IPCC (International Panel on Climate Change) A1B emission scenario for the 21st century using three process-based models; A 20-year set (1991–2010) of observed daily climate data from Aarslev, Denmark was used to form the baseline, from which the RCM data were generated. The simulation of crop growth was performed with increasing carbon dioxide (CO2) levels and under continuous mono-cropping system at different N input rates. Results indicated that grain yield and grain N will be reduced in the future despite increased CO2 concentration in the atmosphere. While the increased N input may increase yield, it will not increase grain N. The present study suggested that in Denmark, alternative strategies for organic N acquisition of plants must be developed. Statistical analyses showed that while the crop models were the main source of uncertainty in estimating crop performance indicators in response to climate change, the choice of RCM was the main source of uncertainty in relation to baseline estimations.