Field Crops Research最新文献

{"title":"Environmental conditions outweigh seeding rates for cover crop mixture performance across the Northeast US","authors":"","doi":"10.1016/j.fcr.2024.109564","DOIUrl":"10.1016/j.fcr.2024.109564","url":null,"abstract":"<div><h3>Context or problem</h3><p>Cover crop mixtures that include complementary species can increase resource use efficiency, total cover crop biomass, and agroecosystem benefits. In the northeastern US, farmers need information on how climatic, environmental and management factors influence the performance of various cover crop mixtures. The development of site-specific seeding rates may be necessary to optimize cover crop mixture services and increase farmer adoption.</p></div><div><h3>Objective or research question</h3><p>The aim of this study was to characterize how site conditions influence mixture performance across the northeastern US, with total shoot biomass, species evenness (yield distribution of constituent species), and seed cost used as metrics of performance.</p></div><div><h3>Methods</h3><p>A field experiment was implemented at seven research farms across a latitudinal gradient in the northeast US, spanning from Maryland to Maine. Monocultures and 12 bicultures were established at 0 %, 25 %, 50 %, 100 %, and 150 % of the recommended rate of that species in monoculture. Winter cover crops from three plant families were planted: cereal rye (grass; <em>Secale cereale</em> L.), hairy vetch (legume; <em>Vicia villosa</em> Roth), and forage rape (brassica; <em>Brassica napus</em> L.), which were selected for their differing functional traits and popularity among northeastern growers.</p></div><div><h3>Results</h3><p>Classification and regression tree analysis showed that climate variables (spring growing degree days, hardiness zone) and soil conditions (soil nitrogen, pH, organic matter) were more influential on cover crop mixture performance than seeding rates of the constituent species. As soil inorganic nitrogen stocks increased, hairy vetch competitiveness and overall shoot biomass decreased compared to cereal rye or forage rape. Cereal rye dominated at sites with colder winters due to its winter hardiness compared to the other species. Forage rape shoot biomass was highly dependent on climate and performed poorly at colder sites.</p></div><div><h3>Conclusions</h3><p>In order to maximize mixture performance, it is important to understand initial soil nitrogen levels if including legumes. Sites with milder winters had more flexibility in species selection and could use lower seeding rates compared to colder sites to produce high yielding, multi-functional mixtures at lower overall seed costs. In colder climates, it is important to include cereal rye to ensure productive mixtures that establish early and are winter hardy.</p></div><div><h3>Implications or significance</h3><p>Understanding anticipated growing degree days in the cover crop season and baseline soil fertility is key when selecting species and seeding rates to ensure high performance of multi-functional mixtures.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sheep grazing increases the forage yield and reduces the yield-scaled soil CO2 emissions of sown pastures in an inland arid region","authors":"","doi":"10.1016/j.fcr.2024.109573","DOIUrl":"10.1016/j.fcr.2024.109573","url":null,"abstract":"<div><h3>Context</h3><p>Forage species are widely planted in arid and semi-arid agro-pastoral regions to increase livestock carrying capacity and thereby relieve excessive grazing pressure. The effect of grazing on forage yield and relevant soil CO₂ emissions in sown pastures converted from cropland remains unclear.</p></div><div><h3>Objective</h3><p>The main objective of the study was to investigate the effect of utilization methods (grazing vs. haying) on annual and perennial forage yields and soil CO₂ emissions during the growing seasons in saline cropland soils and to derive the optimum number of continuous utilization years based on the combined consideration of forage productivity and soil CO₂ emission.</p></div><div><h3>Methods</h3><p>Stands of annual and perennial forage species were established in a saline cropland area of northwest China in a 4-year experiment to investigate the effect of sheep grazing and haying on soil CO₂ emissions during the growing seasons. The relationships between soil CO₂ fluxes and soil properties were fitted. In addition, yield-scaled soil CO₂ emissions were used as an index to evaluate forage productivity.</p></div><div><h3>Results</h3><p>Grazing significantly increased the mean forage yield by 44 % and 14 % over that of haying, and significantly decreased the mean yield-scaled soil CO₂ emissions (CO₂ emission intensity, CO₂EI, kg of CO₂ kg⁻¹ of dry forage yield) by 36 % and 23 % over that of haying in the annual and perennial stands, respectively, from 2014 to 2017. Grazing did not differ from haying for cumulative soil CO₂ flux during the growing seasons in the annual forages but had 17 % lesser (<em>P</em> &lt; 0.05) cumulative CO₂ flux in the perennial forages in 2015. A negative correlation (<em>r</em> = –0.55, <em>P</em> &lt; 0.05) between soil CO₂ flux and soil water content was found in the perennial forages but not in the annual forages. Multiple linear regression results indicated that soil temperature accounted for ≥ 72 % of the variation in soil CO₂ flux. Results of the structural equation model indicated, whether annual or perennial sown pastures, that grazing had the greatest positive effect on forage yield and the greatest negative effect on soil CO₂EI.</p></div><div><h3>Conclusion</h3><p>Grazing mainly reduced the soil CO₂EI by increasing forage yield in annual sown pastures and by reducing soil respiration in perennial pastures. Grazing is the optimal approach to improving forage production while mitigating soil CO₂ emissions in sown pasture in continental arid regions.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MP3, a quantitative trait locus for increased panicle number, improves rice yield potential in Japan by connecting with high source and translocation traits","authors":"","doi":"10.1016/j.fcr.2024.109566","DOIUrl":"10.1016/j.fcr.2024.109566","url":null,"abstract":"<div><h3><em>Context:</em> I</h3><p>ncreasing rice yield potential is an important strategy for meeting rising food demand and achieving global food security. <em>MP3</em> was recently identified as a quantitative trait locus (QTL) in rice that increases panicle number and thereby sink size (the total number of spikelets per square meter). Under current climatic conditions, <em>MP3</em> did not increase grain yield in a high-yielding cultivar in the absence of improved source traits.</p></div><div><h3><em>Objective:</em></h3><p>This study aimed to determine whether <em>MP3</em> increases grain yield in a rice cultivar background with improved biomass production and to analyze the key variables linked to yield improvement.</p></div><div><h3>Methods</h3><p>Two-year experiments were carried out on a paddy field with nitrogen (N) applications in Tsukuba, Japan. Near-isogenic <em>MP3</em> lines, Hokuriku 193-<em>MP3</em> and IR64-<em>MP3</em>, were used in conjunction with their parental cultivars. Hokuriku 193 is a high-yielding cultivar in Japan with high biomass production, and IR64 is a high-yielding mega-cultivar in the tropics.</p></div><div><h3>Results</h3><p>Both Hokuriku 193-<em>MP3</em> and IR64-<em>MP3</em> increased panicle quantity and sink size when compared to the parental cultivars, regardless of N treatment. Hokuriku 193-<em>MP3</em> had a 7 % higher grain yield than Hokuriku 193; however, IR64-<em>MP3</em> did not yield more than IR64. Hokuriku 193 and Hokuriku 193-<em>MP3</em> had larger leaf areas, higher biomass, and accumulated more non-structural carbohydrate (NSC) in the culms and leaf sheaths at heading than IR64 and IR64-<em>MP3</em>. Hokuriku 193-<em>MP3</em> significantly reduced the NSC level in the culm and leaf sheaths at 16 d after heading and had a higher harvest index than Hokuriku 193; however, IR64-<em>MP3</em> did not differ from IR64 with regard to these variables.</p></div><div><h3>Conclusion</h3><p>Hokuriku 193 has surplus source and translocation abilities that can fill the <em>MP3-</em>enlarged sink, resulting in a higher grain yield. In comparison, IR64 lacks these abilities. These findings imply that <em>MP3</em> has boosted the yield potential of rice cultivars in Japan, with Hokuriku 193 having the highest yield in Japan.</p></div><div><h3>Significance</h3><p>This study shows that balanced improvements in sink, source, and translocation are essential for increasing rice yield potential. <em>MP3</em> and the high source and translocation traits of Hokuriku 193 could benefit future high yield breeding initiatives around the world.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlled irrigation can mitigate the greenhouse effects of rice paddy fields with long-term straw return and stimulate microbial necromass carbon accumulation","authors":"","doi":"10.1016/j.fcr.2024.109571","DOIUrl":"10.1016/j.fcr.2024.109571","url":null,"abstract":"<div><h3>Context and problem</h3><p>The overall greenhouse effects of rice paddy fields are influenced by the balance between greenhouse gas (GHG) emissions and soil organic carbon sequestration (SOCS). Studies on how straw return impacts GHG emissions and SOCS under different water regimes—specifically, conventional irrigation (CI) and alternate wetting and moderate drying (AWMD)—are crucial for developing strategies to mitigate the greenhouse effect in rice paddy fields.</p></div><div><h3>Objective</h3><p>This study aimed to develop a strategy for decreasing GHG emissions, improving SOCS, and increasing grain yield of rice paddy fields under long-term straw return.</p></div><div><h3>Methods</h3><p>Different water regimes were introduced after six years of straw return in the rice paddy field, and there were four treatments: straw removal and CI (N-CI), straw removal and AWMD (N-AWMD), straw return and CI (R-CI), and straw return and AWMD (R-AWMD). We studied various traits related to soil organic carbon sequestration capacity and GHG emissions over three years to investigate the effects of combination of AWMD and straw return on the GHG emission from paddy field.</p></div><div><h3>Results</h3><p>Straw return significantly increased net greenhouse gas emissions (NGHGE) and seasonal soil total organic carbon sequestration rate (TOCSR) due to substantial quantity of straw inputs. On average, straw return increased NGHGE by 2.125 t CO₂ ha^–1 and TOCSR by 393.2 kg C ha^–1, respectively. AWMD could mitigate the greenhouse effects caused by straw return by decreasing NGHGE by 28.0 %, primarily attributed to the reduction in CH₄ emissions (-27.0 %), which outweighed the effects of increased N₂O and CO₂ emissions. Although AWMD did not increase the overall soil organic carbon (SOC) content, it optimized the composition of SOC by increasing the percentage of microbial-derived C, including fungal necromass C (FNC) and bacterial necromass C (BNC), which are more stable than plant-derived C. The aerobic environment in AWMD combined with straw return enhanced the activities of microbes, which promoted the conversion of plant residue C to FNC and BNC and improved soil carbon sequestration.</p></div><div><h3>Conclusions</h3><p>The combination of straw return with AWMD can reduce GHG emission, and optimize soil carbon sequestration by stimulating microbial necromass carbon accumulation.</p></div><div><h3>Implication</h3><p>This study offers valuable insights into mitigating GHG emissions and enhancing soil organic carbon sequestration in high-yielding rice system through the combined adoption of AWMD and straw return.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized controlled-release nitrogen strategy achieves high yield and nitrogen use efficiency of wheat following rice in the lower reaches of Yangtze River of China","authors":"","doi":"10.1016/j.fcr.2024.109567","DOIUrl":"10.1016/j.fcr.2024.109567","url":null,"abstract":"<div><h3>Context and problem</h3><p>Wheat following rice manly distributed in the lower reaches of Yangtze River of China, its major challenge is to cope with simultaneous improvement in yield and nitrogen use efficiency (NUE) without increasing the input of fertilizer.</p></div><div><h3>Objective</h3><p>Controlled-release urea (CRU) offer several advantages in agricultural practices. However, the effectiveness of CRU was strongly affected by the application strategy, types and region environmental conditions. This study investigated if and how the controlled-release nitrogen strategy could achieve high yield and high NUE.</p></div><div><h3>Methods</h3><p>Field experiments across two years using two spring wheat varieties were conducted with five nitrogen application treatments, including no nitrogen (T1), conventional urea (T2, CK), controlled-release urea (T3), CRU combined with one-time basal CU (T4) and CRU combined with split CU (T5).</p></div><div><h3>Results</h3><p>The results showed that yield and NUE were significantly increased in optimized controlled-release nitrogen strategy (T4 and T5) compared to T2, especially for T4. T4 significantly improved biomass accumulation after anthesis, non-structural carbohydrates remobilization and harvest index (HI), increased nitrogen absorption and nitrogen harvest index (NHI), enhanced leaf photosynthetic capacity (leaf area index, photosynthetic rate, chlorophyll content) and leaf nitrogen metabolism enzyme activities. The diversity of nitrogen-fixing microorganisms and relative abundance of Bradyrhizobium in rhizosphere after anthesis were significantly increased in T4. Correlation analysis showed that the above morpho-physiological indexes were positively and significantly correlated with grain yield and NUE.</p></div><div><h3>Conclusions</h3><p>This study indicates that the appropriate combined application strategy (CRU combined with one-time basal CU) could hold great promise to increase yield and NUE of wheat via facilitating carbon-nitrogen allocation and optimizing rhizosphere environment in the lower reaches of Yangtze River of China.</p></div><div><h3>Implication</h3><p>This study would offer theoretical basis for achieving high yield and nitrogen use efficiency through combined application strategy of controlled-release and convention urea, and provide practical guidance in high efficiency production in wheat-rice rotation system.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change induced heat and drought stress hamper climate change mitigation in German cereal production","authors":"","doi":"10.1016/j.fcr.2024.109551","DOIUrl":"10.1016/j.fcr.2024.109551","url":null,"abstract":"<div><h3>Context</h3><p>Agricultural production and climate change strongly influence each other and there are significant efforts to minimize negative impacts in both directions. In particular, breeding progress has succeeded in reducing the carbon footprint (CFP) of cereals over time. However, there is widespread certainty that climate change-related weather extremes have led to stagnation of cereal yields in many global production regions.</p></div><div><h3>Research question</h3><p>We assume that climate change-related yield stagnation is also evident in variety trials in Germany, which has to date only been shown for on-farm yields. Furthermore, we expect that the stagnation in yields also leads to a stagnation in the downward trend of CFP, and that heat and drought stress in particular increase the CFP of cereals. In addition, we hypothesize that the site-specific soil quality largely determines stress induced increases in CFP.</p></div><div><h3>Methods</h3><p>We conduct a partial life cycle assessment (LCA) with German variety trial data from 1993 to 2021 and determine the greenhouse gas emissions per unit of land (GHGL), as well as the CFP of winter wheat, winter rye, and winter barley. Further, we evaluate the time trends of yield, GHGL, and CFP using linear and quadratic plateau models. In addition, we calculate spatio-dynamic weather indices (WIs) for moderate, severe and extreme heat and drought stress. Using mixed models, we estimate the explanatory power and effect size of heat and drought WIs on the CFP. Finally, we present the spatial differences of heat and drought on the CFP at different soil qualities.</p></div><div><h3>Results</h3><p>We show yield plateaus in all crops and stagnating GHGL trends, resulting in a stagnation of the downward trend of CFP, especially for rye and barley. We highlight that heat and drought increase the CFP of all crops. However, the impact of heat and drought on the CFP varies greatly with soil quality across all crops.</p></div><div><h3>Conclusions</h3><p>We conclude that climate change-induced weather extremes are major challenges not only for cereal production and food security but also for climate change mitigation in the agricultural sector, highlighting the importance of high-yield locations, alongside variety selection and resource-efficient management, for climate change mitigation.</p></div><div><h3>Significance</h3><p>This study is the first that proves significant yield stagnation in German variety trials. Moreover, this study is the first to analyze the impact of heat and drought stress on cereal CFP, with novel results that proof that climate adaptation will become a crucial aspect of climate change mitigation in field crops.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378429024003046/pdfft?md5=c2cd79bbb01ae91271f47731e425093d&pid=1-s2.0-S0378429024003046-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key factors influencing wheat grain zinc and manganese concentration in areas with different soil available phosphorus","authors":"","doi":"10.1016/j.fcr.2024.109558","DOIUrl":"10.1016/j.fcr.2024.109558","url":null,"abstract":"<div><h3>Context or problem</h3><p>Zinc (Zn) deficiency and manganese (Mn) excess in wheat grains caused by high soil phosphorus (P) (&gt;15 mg kg⁻¹) in alkaline soil have been widely reported. How to identify the key factors influencing wheat grain Zn and Mn concentration in the areas with different soil available P (SAP) levels and meanwhile achieve high-Zn and low-Mn in grains needs to be resolved.</p></div><div><h3>Objectives</h3><p>In the present research, we collected soil and plant samples from 273 fields of alkaline soils (pH 7.5–9.4) in northern China for two years to analyze the comprehensive influences of soil P (4.6–58.1 mg kg⁻¹) and other soil physico-chemical properties on the content of Zn and Mn in wheat grains.</p></div><div><h3>Results</h3><p>Results and the structural equation model demonstrated that low soil available phosphorus (SAP), high soil NO₃^--N (SNN), and DTPA-Zn were beneficial for improving the grain Zn concentration; low SAP, high SNN, and lower DTPA-Mn were beneficial for decreasing grain Mn concentration. Samples of wheat grain Zn concentration &gt; 40 mg kg⁻¹ were found in the fields with SAP &lt; 15 mg kg⁻¹. The increase of SNN could significantly increase grain Zn when SAP &lt; 15 mg kg⁻¹ or &gt; 30 mg kg⁻¹; when SAP at 15–30 mg kg⁻¹, only regulating SNN content did not increase grain Zn, grain Zn was significantly and positively correlated with soil DTPA-Zn. To decrease wheat grain Mn to lower than 48.7 mg kg⁻¹ (the recommended safe threshold), SAP should be lower than 30 mg kg⁻¹.</p></div><div><h3>Conclusion</h3><p>In conclusion, this research clarified the key soil factors influencing wheat grain Zn and Mn concentration in areas with different SAP levels, and by optimizing the application of N and P fertilizer and improving exogenous Zn application, high grain Zn while maintaining low Mn levels can be achieved with different SAP levels.</p></div><div><h3>Implications</h3><p>The findings of this study provide theoretical and technical support for guiding wheat production with high yield and high quality.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The long-term nitrogen fertilizer management strategy based on straw return can improve the productivity of wheat-maize rotation system and reduce carbon emissions by increasing soil carbon and nitrogen sequestration","authors":"","doi":"10.1016/j.fcr.2024.109561","DOIUrl":"10.1016/j.fcr.2024.109561","url":null,"abstract":"<div><h3>Problem</h3><p>Facing the multiple objectives of increasing production, carbon sequestration, and nitrogen reduction in farmland, optimizing straw and nitrogen fertilizer management to achieve a balance between grain production and ecological safety in the wheat-maize rotation system has become increasingly critical and urgent.</p></div><div><h3>Methods</h3><p>This study conducted a five-year field experiment in the Guanzhong Plain of China from 2017 to 2021 to investigate the effects and synergistic regulatory mechanisms of straw disposal methods (straw return, no-straw return) and nitrogen application rates (0, 150, 225, 300 kg ha⁻¹) during the maize season on soil greenhouse gas (GHG) emissions, crop yield, and soil organic carbon (SOC) and soil toatl nitrogen (STN) content.</p></div><div><h3>Results</h3><p>The results showed that under the scenario of no-straw return, fertilization increased soil nitrous oxide (N₂O) emissions by 35.9–64.0 %, and annual total crop yield by 16.4–22.8 %; however, under the straw return scenario, the increase in soil N₂O emissions due to fertilization decreased to 26.7–62.0 %, while the yield increase rose to 19.5–25.9 %. The interaction effect between straw return and nitrogen application was significant, with straw return boosting the contribution rate of nitrogen application to yield (2.2–4.4 %) and simultaneously reducing the contribution rate of nitrogen application to N₂O emissions (3.0–27.5 %). The study also indicated that the yield-increasing effect of straw return continued to increase with the duration of straw return, with the contribution rate to yield reaching 9.9 % after three years of continuous straw return, while the contribution rate of nitrogen application to yield increased by an average of 3.0 % per year. This suggests that there is significant potential for coupling straw return with reduced nitrogen application. Straw return combined with nitrogen fertilizer increased SOC content by 7.9–40.1 % and 3.7–12.5 %, STN content by 1.0–22.8 % and 6.1–13.9 %, respectively, compared to sole nitrogen application and sole straw return. Pathway analysis indicated that straw return combined with nitrogen fertilizer mainly enhanced soil carbon-nitrogen sequestration, improved fertilizer utilization efficiency and crop nutrition levels, reduced net global warming potential (GWP) and greenhouse gas intensity (GHGI), and synergistically regulated to increase yield while reducing GHG emissions.</p></div><div><h3>Conclusion</h3><p>The study highlights that straw return lowers the threshold for nitrogen application levels, suggesting that regulating nitrogen application levels between 224 and 256 kg ha⁻¹ during the maize season, and maintaining a nitrogen application level of 195 kg ha⁻¹ during the wheat season, is beneficial for long-term stable production and emission reduction in the wheat-maize rotation system farmland.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142121755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Greenhouse gas emissions during the rice season are reduced by a low soil C:N ratio using different upland-paddy rotation systems","authors":"","doi":"10.1016/j.fcr.2024.109562","DOIUrl":"10.1016/j.fcr.2024.109562","url":null,"abstract":"<div><h3>Context</h3><p>Upland<strong>-</strong>paddy rotation can improve multiple-cropping index and crop yields; however, the mechanisms underlying the effects of dry-season crop diversification on rice yields and greenhouse gas (GHG) emissions under multiple rotation systems remain unclear.</p></div><div><h3>Objective</h3><p>Here, we aimed to clarify the intrinsic mechanisms whereby rice yields and GHG emissions respond to the diversification of dry-season crops and lay a theoretical foundation for developing agronomic measures that can stabilize yields and reduce GHG emissions.</p></div><div><h3>Methods</h3><p>Using a positioning experimental site for upland-paddy rotation, we measured rice-season CH₄ and N₂O emissions, crop yields, GHG-emission intensity (GHGI) levels, soil physical and chemical properties in garlic–rice (GR), wheat–rice (W<em>R</em>) systems for 3 years (2019–2020, and 2022), and in a rapeseed–rice (RR) system for 1 year (2022). The soil microbial dynamics of the three systems were only tested in 2022.</p></div><div><h3>Results</h3><p>The W<em>R</em> system had the highest CO₂ emission equivalent (CO₂-eq), with a 3-year interval value of 1898.24–16794.30 kg·ha⁻¹, the lowest yield (8490.10–9773.46 kg·ha⁻¹), and the highest GHGI (0.22–1.83). The GR system had the highest rice yield (9718.91–10769.75 kg ha⁻¹), a lower CO₂-eq (1588.55–12567.51 kg·ha⁻¹), and therefore a lower GHGI (0.16–1.24). The RR system had the lowest GHGI in 2022 (benefiting from the lowest CO₂-eq) and a slightly higher yield than that of the W<em>R</em> system. CH₄ contributed to &gt;88 % of the CO₂-eq under the three systems in 2020 and 2022. The higher soil C:N ratio of the W<em>R</em> system stimulated methanogenic microorganisms, coupled with higher microbial biomass C levels, and ultimately increased CH₄ emissions substantially. The soil C:N ratios of the GR and RR systems were significantly lower than that of the W<em>R</em> system because the soil total nitrogen (TN) of both systems was higher and increased CH₄ emissions were avoided. The higher levels of N nutrients (TN, NO₃^--N, and NH₄⁺-N) in the GR and RR systems also enhanced rice yields, with respective increases of 10.37 % and 1.22 %, compared with that of the W<em>R</em> system.</p></div><div><h3>Conclusions</h3><p>The diversified cultivation of dry-season crops in upland-paddy rotation systems affected rice yields and GHG emissions by changing the ratios of C and N.</p></div><div><h3>Implications</h3><p>Our findings highlight the importance of future research involving comprehensive agronomic measures to help reduce emissions, including fertilizer management, straw management, and tillage methods.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Straw return under deep tillage increases grain yield in the rice-rotated wheat cropping system","authors":"","doi":"10.1016/j.fcr.2024.109559","DOIUrl":"10.1016/j.fcr.2024.109559","url":null,"abstract":"<div><h3>Context</h3><p>Straw return under rotary tillage has been used for two decades in the rice-rotated wheat cropping system in the lower Yangtze region of China, but it has become prone to reduce wheat emergence and yield in recent years, and alternative tillage methods are required to ensure the high wheat yields.</p></div><div><h3>Aims</h3><p>To determine whether straw return under deep tillage can improve wheat yield and under what mechanisms. We hypothesize that straw return under deep tillage can increase wheat seedling number by reducing rice stubble and straw coverage, and expand the nutrient pool and root system of the plow soil profile to keep post-anthesis viability for increasing wheat yield.</p></div><div><h3>Methods</h3><p>A field study was conducted during two consecutive years and included four treatments: rotary tillage after straw removal (RT); rotary tillage after straw return (RTS); shallow rotary tillage followed by straw mulch (STS) and deep tillage after straw return (DTS). Wheat seedling number, yield, aboveground nutrient uptake, growth period, root characteristics, and soil nutrients were measured.</p></div><div><h3>Results</h3><p>Compared to RT, seedling number under RTS and STS decreased by 8.3 % and 13.4 %, respectively, while DTS increased by 14.7 %. Wheat yield under RTS and STS decreased by 3.0 % and 7.3 %, respectively, while DTS increased by 8.2 %. The reduction in seedling number under RTS and STS would be partially offset in wheat yield by an increase in effective tiller number per plant and grain weight. Consequently, the variation in wheat yield among treatments was less than the variation in seedling number. Aboveground N and P accumulation in wheat under DTS were higher than the other treatments. Among four treatments, DTS had the highest root distribution and soil N and P contents in the middle and deep soil layers, thus prolonged grain filling duration. Wheat nutrient uptake at maturity and yield were significantly correlated with root weight density and root length density in both middle and deep soil layers.</p></div><div><h3>Conclusions</h3><p>Straw return under deep tillage can increase nutrient supply capacity and root distribution in deep soil while ensuring wheat emergence, enabling better filling of post-anthesis wheat and yield. It is therefore an effective alternative tillage method suitable for the rice-rotated wheat cropping system.</p></div>","PeriodicalId":12143,"journal":{"name":"Field Crops Research","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}