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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]

Dwarf mutants identified from various crop species have been extensively used as valuable resources for breeding lodging resistant elite cultivars. The response of dwarf lines to gibberellic acid 3 (GA3) is important for dwarf mutant identification and classification. Forty- eight foxtail millet [Setaria italica (L.) P. Beauv.] dwarf lines collected from different breeding programs in China were tested for their response to GA3 at the seedling stage. Forty-six of the samples were identified as being sensitive to GA3 treatments and two lines, 84l33chunhe and Xianai, were identified as insensitive. For most sensitive lines, seedling, leaf, mesocotyl, and coleoptile showed positive reaction to GA3 increasing their length at most of the concentrations. Root responses to GA3 were diverse but mostly negative. The mesocotyl is the most sensitive to GA3 solutions with concentrations between 30 and 50 mg kg-1 and is suggested as the best test for gibberellic acid (GA) sensitivity in foxtail millet. The results in this paper indicate that multiple dwarfing genes might exist in foxtail millet and that these dwarf lines will be useful for further studies. [ABSTRACT FROM AUTHOR]

Snap bean (Phaseolus vulgaris L.) is the vegetable form of common bean, and regarded as one of the most important and commonly consumed products in the world. In this study, 221 snap bean core accessions mostly from China were characterized the genetic diversity, gene pool identity, and relationships using 30 microsatellite markers, and concurrently evaluated for phenotype traits and phaseolin patterns. A total of 140 alleles were detected with an average of 4.67 per locus. The polymorphic information content ranged from 0.215 to 0.823, with an average of 0.488. Nei's genetic distances between accessions ranged from 0 to 0.9999, with an average of 0.6143. In those Chinese snap beans, structure analysis proved the existence of a high proportion of hybrid accessions except for identification of Andean and Mesoamerican gene pools. Neighbor‐joining clustering and principal coordinate analysis based microsatellite markers were similar in explaining the extent of diversity with both revealed Andean and Mesoamerican gene pools, which were divided into seven subgroups. Four of those subgroups, including one arising from introgression, were identified as belonging to the Andean gene pool, which likely represented Nueva Granada and Peru races. Other three subgroups were identified as belonging to the Mesoamerican gene pool, which likely represented the Mesoamerican race, owing to their close association with the control genotype. The diversity index of the qualitative traits was 0.80 to 1.88, with the average value of 1.20, while the diversity of the quantitative traits was ranked as 100‐seed weight (H′ = 1.98) > pod length (H′ = 1.90). Six principal components explained 69.13% of the total variation. Eight phaseolin patterns were identified in the 221 accessions. This study demonstrated the gene pool, as well as geographical, diversity of snap bean germplasms in China. The substantial diversity level is important for the utilization and conservation of snap bean, as well as future breeding programs. Core Ideas: The distinction in snap bean of China has blurred between Andean and Mesoamerican pools for obvious introgression.The combination of microsatellites, phaseolin, and phenotypic traits is effectively evaluated for genetic diversity.Phaseolin can separate two gene pools but not be well detected population structure and new variation. [ABSTRACT FROM AUTHOR]

This study aimed to assess the impact of climate change on spring wheat production and to provide more accurate projections by directly investigating the effect of climate change on crop development and yield. Based on ground observation data from 1981 (1986 Dingxi) to 2020 in four case areas in northwest China, and the relationships among spring wheat growth, yield, and climate factors were analyzed and determined. The results showed that the extreme arid (Dunhuang) and semiarid regions (Dingxi) tend to be warmer and wetter, whereas arid regions (Wuwei) and semihumid regions (Linxia) tend to be warmer and drier. Correlation analysis indicated that yield of spring wheat in Wuwei, Dingxi, and Linxia Stations increased significantly. The decrease in the number of days (≥30 °C) during the growth period at Wuwei resulted in a significant yield increase in the past 40 years. At Dingxi, yield increased over the last 35 years due to the significant increases in precipitation during growth, the number of grains per panicle, and thousand‐grain weight, and the decrease in infertile spikelets. Further increase in global temperature and changes in future precipitation patterns will likely affect spring wheat production in northwest China. Core Ideas: The relationship between climate factors and growth and yield of spring wheat are explored.Dominant climatic factors affecting the growth of spring wheat in different climatic regions of northwest China are studied.Regional differences in spring wheat growth and yield in response to climate change are assessed.Climate change trends in different climatic regions over time are examined.Impact of climate change on crop development and yield are assessed. [ABSTRACT FROM AUTHOR]

Balanced fertilization is one of the most critical management factors for attaining high yields. Assessing pod yield and plant nutrient demand can provide theoretical guidance for fertilization management of high yielding peanut (Arachis hypogaea L.). Following this rationale, a large dataset was collected from field experiments (n = 313) across the main peanut planting regions of China for a period spanning from 2000 to 2019 to evaluate nutrient uptake behavior of peanut under current optimum fertilization management. Across the entire dataset, the results showed that average peanut pod yield and harvest index (HI) were 4.5 Mg ha-1 and .54, respectively. The average peanut nitrogen (N), phosphorus (P), and potassium (K) requirements were of 48, 7.1, and 21 kg Mg-1 pod yield, respectively. Across five ranges of pod yields (<3, 3-4, 4-5, 5-6, and >6 Mg ha-1), both nutrient uptake and HI increased with increasing pod yield. The N and K requirements (kg Mg-1) decreased with increasing pod yield, respectively, mainly due to reductions in pod N and K concentrations. The P requirement increased with yield, attributed to an increase in straw P concentration as P luxury uptake occurs under high pod yield. [ABSTRACT FROM AUTHOR]

Soil sodicity and salinization is a major issues concerning agricultural production in northeast China. The effects of six treatments—no tillage (NT), no tillage and subsoiling (NTS), rotary and ridge tillage (RT), rotary and ridge tillage and subsoiling (RTS), rotary and flat tillage (FT), and rotary and flat tillage and subsoiling (FTS)—on soil physical and chemical properties and yields were compared from 2016 to 2018. The results showed that compared with the RT treatment, which is the traditional tillage method in this area, and the FT treatment, the NT treatment increased the soil water content (SWC) during the first‐leaf growth stage (V1). The use of subsoiling increased the average daily temperature and the soil thermal time (TTsoil). Subsoiling contributed to the growth and development of deep roots and increased leaf area index (LAI) to intercept more radiation. The NTS treatment increased grain yield of maize (Zea mays L.) by 2.7–15.2%, nitrogen use efficiency (NUE) by 4.2–14.4%, and water use efficiency (WUE) by 5.4–16.5% compared with RT. In conclusion, NTS soil management practices appear to be a sustainable approach to farming in the semiarid region of the Songnen Plain. Core Idea: Subsoiling reduced the BD and increased the SWC and average daily temperature.The NT treatment reduced soil salinity. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) kernel moisture content at physiological maturity significantly differs among hybrids and is affected by the environment. Nonetheless, 35% was previously reported and is widely accepted as the moisture content at physiological maturity. To verify whether the 35% moisture content could be applied to various hybrids and regions, a multi‐area, multi‐year trial was conducted from 2015 to 2018 in six locations in different maize‐planting regions of China. Time‐series kernel moisture contents and kernel dry weights were investigated for 156 hybrids in total to ascertain the growth pattern of the percentage maximum kernel dry weight as a function of kernel moisture content. The growth patterns were fitted with a tri‐linear model with a plateau, and at the point at which the percentage maximum kernel dry weight first reached its maximum (physiological maturity), the kernel moisture contents were 32% for summer maize, 34% for spring maize, and 38% for Daqing (a special spring maize region). We found that regional variation existed in kernel moisture content at physiological maturity. The regional average moisture content at physiological maturity could thus be used as an indicator to determine physiological maturity for most hybrids in the region. In addition, varietal differences in moisture content could be accounted for when using the regional average value. [ABSTRACT FROM AUTHOR]

Identifying the agronomic optimal plant density (AOPD) for maximum grain yield is essential to develop enhanced management strategies for maize (Zea mays L.) production. In this study, we used a boundary‐line method to examine the yield response of maize to plant density in China, based on the metadata (2783 data points) gathered from 157 recent studies during 2000–2017. We found the AOPD was 8.5 × 104 plants ha−1 in Northeast China, 9.3 × 104 plants ha−1 on the North China Plain, 10.5 × 104 plants ha−1 in Northwest China, and 8.0 × 104 plants ha−1 in Southwest China. Compared with current practices, potential grain yield with these AOPDs was improved by 13–20% for these major maize regions of China. Across regions, AOPDs were similar for spring‐planted (9.2 × 104 plants ha−1) and summer‐planted maize (9.3 × 104 plants ha−1) systems, although grain yield at the AOPD was 7% greater for the spring‐planted maize system. For different productivity environments, we found that high‐yielding plots obtained a yield of 18.2 Mg ha−1 at an AOPD of 11.6 × 104 plants ha−1, whereas in general productivity plots, 39% lower grain yield was achieved with a 19% lower AOPD (9.4 × 104 plants ha−1). In summary, this study illustrated AOPDs with modern maize hybrids for different productivity environments, cropping systems, and regions. Further study is needed to investigate the possible influence of agronomic factors such as lodging risks by increasing plant density. [ABSTRACT FROM AUTHOR]

For effective use of the factor‐analytic (FA) model in analyzing data from multi‐environmental trials (METs), we undertook an empirical study of data sets from the corn (Zea mays L.) performance trails in China to compare all FA models with possible number of factors. We found that for the variety main effects, the estimate, ranking, and test efficiency of contrast were compatible among the FA models with various numbers of factors. For the variety simple effects, the effect estimate, and hence the ranking, changed; the test efficiency of contrast and discrimination power increased with increasing number of factors as the number of factors was smaller than a specific number. With consideration of both test efficiency of contrast and discrimination power of varieties for the trials analyzed, about 10 could be chosen as the optimal number of factors of the FA model approach. [ABSTRACT FROM AUTHOR]

Straw incorporation (SI) is considered a valid agricultural measure for ameliorating soil quality and sequestrating soil C. This study aimed to quantitatively summarize the response of cereal yield to SI management. Our results showed that compared with straw removal, SI could significantly enhance cereal yield by 7% over all of China across the 9-yr period. In all regions, SI in coarse-textured soils increased yields more than in fine-textured soils. Straw incorporation resulted in greater yield increases for upland crops compared with rice (Oryza sativa L.) cropping, and for rotary tillage compared with plowing and no tillage. Overall, SI-induced cereal yield increases were greater in areas with a lack of soil nutrients and soil water. The SI-induced increases of 1 t ha-1 of soil organic C (SOC) storage could increase cereal yield by 44 kg ha-1. If half or full amounts of cereal straw is returned across all of China's agricultural regions, cereal yields would increase by an average of 2.84 and 5.07 Tg yr-1, respectively, which would contribute to achieving the increasing yield requirements of China. [ABSTRACT FROM AUTHOR]

Production protocols for the cultivation of highyielding and high-quality Salvia miltiorrhiza Bunge are needed because of the expanding markets for high-value Danshen. A 2-yr pot experiment was conducted to investigate the effect of nitrogen (N) levels and ratios of ammonium nitrogen (NH4+ +-N) to nitrate nitrogen (NO3--N) on root development and contents of bioactive components of S. miltiorrhiza Bunge in a soil culture system. The S. miltiorrhiza Bunge seedlings were provided with three N levels (0, 3, and 6 g N plant-) at the same NH4+:NO3- ratio (0:100) and five NH4:NO3- ratios (0:100, 25:75, 50:50, 75:25 and 100:0) at the same N level (3 g N plant-1). The plant dry matter (DM), the apparent property of roots, and the contents of cryptotanshinone, tanshinone IIA, total tanshinones, danshensu, and salvianolic B in roots were examined. Plant growth and all the contents of the bioactive components responded negatively to increasing N availability, suggesting that S. miltiorrhiza Bunge is not a nitrophile. The best apparent property of roots and the highest DM were consistently observed when the NH4+:NO3- ratio was 75:25. However, the NH4+:NO3- ratios required for the highest content and yield of bioactive compounds varied among the different compounds. Therefore, in the commercial cultivation of S. miltiorrhiza Bunge, the NH4+:NO3- ratio should be chosen according to the target compound, considering the DM and apparent property of roots and the contents of the desired compounds. Further studies are needed to elucidate the mechanisms in terms of photosynthesis, the activities of key enzymes, and the biosynthetic pathway of the bioactive compounds. [ABSTRACT FROM AUTHOR]

Switchgrass (Panicum virgatum L.) is an important feedstock for bioenergy production, but establishment is difficult in cold arid areas. This study determined the conditions required to improve its germination and emergence in the field. Under controlled conditions, the effects of temperature, water status, and light on germination were studied by exposure to 12-h alternating temperatures of 15/5, 20/5, 20/10, 25/10, 35/20, 40/20, and 45/20°C (day/night) and water potentials of 0, -0.2, -0.4, -0.6, -0.8, and -1.2 MPa in culture medium. Maximum percentage germination occurred at 35/20°C, 0 MPa water potential, and in continuous dark. In the field when planted in early spring (April), no emergence occurred when there was no surface cover or covered with straw mulch (SM) whereas using plastic film mulch (FM), emergence reached 383 seedlings m-2 with pre-sowing irrigation but only 273 without irrigation. This was associated with higher soil temperatures and better soil moisture. However, in July seeding, SM lead to better water status and cooler soil conditions and thus better stand establishment. In contrast, FM treatment had poor establishment primarily due to the high temperatures. Our study indicates that emergence of switchgrass in an arid environment was (i) enhanced by pre-sowing irrigation and shallow seeding, (ii) made possible in spring by the use of FM, and (in) improved with SM for summer seeding. [ABSTRACT FROM AUTHOR]

Aquilaria sinensis (Lour.) Gilg, one of the most valuable medicinal plants endemic to China, has been largely destroyed and is presently listed as an endangered species in the China Plant Red Data Book: Rare and Endangered Plants. The number of individuals and population genetic diversity of this species have rarely been reported. A total of 567 polymorphic bands were found in 112 accessions of A. sinensis using Inter-simple sequence repeats and sequence-related amplified polymorphism markers. All accessions from 11 locations were allocated into five geographical natural populations by cluster analysis. The genetic classification of accessions coincided with their geographic distribution, with some overlapping between neighboring regions. Principal coordinate analysis further showed three large-scale geographic genetic zones of A. sinensis. Nei's genetic diversity had low values in the range 0.2014 to 0.1671 at the species level for A. sinensis. There were significant differences (P < 0.001) among (19.64% of the variance) and within populations (80.36% of the variance). Restricted gene flow (Nm = 1.8292) among populations may result from several factors, such as low seed dispersal and isolation of populations. [ABSTRACT FROM AUTHOR]

Cereal cyst nematode (CCN) is becoming one of the important soil-borne pathogens in wheat (Triticum aestivum L.) monocropping or wheatmaize (Zea mays L.)-wheat cropping systems of central China. Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984 was recently recognized as a causal agent of CCN in China, but little information is available on sources of resistance against this nematode species. The present study was initiated to determine the current status of resistance in wheat cultivars against H. filipjevi and to identify effective resources for improvement of CCN resistance in China. A 3-yr field study of CCN resistance that involved 174 wheat cultivars or wheat-Thinopyrum derivatives was conducted in a wheat field in Xuchang, Henan Province, China, where H. filipjevi had been present for years. Greenhouse experiments were conducted with representative resistant entries from each group of accessions. None of the 78 wheat cultivars and breeding lines from China was resistant in field tests. Wheat cultivar Madsen from Washington State was most resistant among the entries tested both in field and under controlled environment. New sources of resistance to H. filipjevi were identified in some wheat-intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] and wheat-tall wheatgrass [Thinopyrum ponticum (Podp.) Barkworth & D. R. Dewey] partial amphiploids, which will diversify resistance resources in enhancing resistance of wheat against CCN. [ABSTRACT FROM AUTHOR]

The high molecular weight gluteniri subunits (IrIMW-GS) are essential in determining breadmaking quality, and knowing their composition can help in making appropriate decisions to improve wheat (Triticum aestivum L.) quality. The HMW-GS compositions of 189 Chinese wheat landraces (CWLs), 61 introduced lines (ILs), and 840 Chinese improved varieties (ClVs) were irivestigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in this study. The aim was to identify novel HMWGS alleles and to compare the genetic diversity ~mong the three groups. A total of 31 HMW-GS alleles and 86 allele combinations were found in all accessions. For CWL and CIV, the predominant pattern was (null, 7+8, 2+12), with a frequency of 71.6 and 26.0%, respectively. The predominant pattern in the IL was (null, 7+9,2+12) with a frequency of 13.6%. The IL had the largest variation and the average index of genetic variation (H). The H was 0.6117, whereas CWL and CIV had H values of 0.2275 and 0.51 61, respectively. In addition, the present study showed that an increase of 7+9 and 5+10 in the CIV came from the use of foreign parents. The results revealed that the IL was an important reservoir for improving Chinese wheat-quality characteristics such as grain protein content, hardness, and sodium dodecyl sulfate (SOS) sedimentation. Although the genetic variation in the CWL was low, it contained novel alleles (lBx7.1* and 1By8.1*), which indicated that this group was also a potential resource for wheat-quality improvement. [ABSTRACT FROM AUTHOR]

We compared yield, genetic gain, and morphology for two sets of maize (Zea mays L.) hybrids using yield test plots grown in China at different pianting densities. One set comprised 29 Chinise maize hybrids that were individually widely grown in China during 1964 through 2001. A second set comprised U.S. hybrids that were used either during the 1960s or during the 2000s. The US. hybrids had higher yields for both 1960s and 2000s comparisons. United States hybrids showed highest genetic gain (81 kg ha-1) at the highest planting density (67,550 plants ha1) whereas the highest rate of gain for Chinese hybrids was 62 kg ha1 at the medium planting density (52,500 plants ha1). Unlike the Chinese hybrids, U.S. hybrids showed significant interaption with planting density. Chronologically, all hybrids showed morphological changes for many characteristics, often at different rates, and occasionally in different directions. Pedig~ree and molecular marker data showed U.S. and Chinese hybrids to be very different germplasm with decades-old U.S. germplasm contributing even to recently developed and widely used Chinese hybrids. Chinese maize agricultural production can rapidly and significantly benefit from adopting breeding and agronomic strategies that allow for improved yield under higher planting densities. [ABSTRACT FROM AUTHOR]