Long-term intensive maize cultivation under subtropical double-cropping systems has resulted in increased compaction and declining fertility. Although conservation tillage and straw return have been widely adopted to improve soil quality, their combined effects on soil physicochemical properties, biological functions across the 0–40 cm soil profile, and maize yield performance remain poorly understood. A six-year field experiment was conducted to evaluate the combined effects of straw management (CK: conventional practice; SR: straw return) and tillage systems (NT: no-tillage; RT: rotary tillage; SS: subsoiling; SS+RT: subsoiling combined with rotary tillage) on the soil physicochemical properties, enzyme activities, microbial biomass carbon (MBC), and maize yield. The integrated SR+SS+RT treatment significantly reduced soil bulk density by 2.57% while increasing soil water content by up to 12.20%. Compared with traditional seeding, straw return increased soil organic carbon (SOC) and total nitrogen (TN) by 8.38% and 13.52%, respectively. Enhanced soil biological activity was also evident, with MBC increasing by 7.70% and substantial enhancements in soil enzyme activities, particularly cellulase (+12.08%) and acid phosphatase (+15.80%). Moreover, the combined SS+RT treatment was associated with a more even vertical distribution of carbon and nitrogen, thereby alleviating nutrient stratification within the soil profile. The grain yield was strongly and positively correlated with sucrase (r = 0.773) and cellulase (r = 0.738) activities, indicating significant associations between selected soil biological indicators and maize yields. Consequently, the SR+SS+RT treatment produced the highest spring and autumn grain yield (9405 and 8696 kg ha−1), compared with SR+NT. Integrating straw return with subsoiling and rotary tillage provides a synergistic strategy for alleviating soil compaction, improving soil physicochemical and biological properties throughout the root zone, and enhancing maize productivity. This integrated management practice offers a sustainable approach for restoring soil fertility and maintaining high crop yields in intensive subtropical agricultural systems.

Increasing planting density is one of the most important strategies for generating higher maize yields. Moderate leaf rolling decreases mutual shading of leaves and increases the photosynthesis of the population and hence increases the tolerance for high-density planting. Few genes that control leaf rolling in maize have been identified, however, and their applicability for breeding programs remains unclear. Here we identified a maize abaxially rolled leaf1 (arl1) mutant with extreme abaxially rolled leaves and found that the size of the bulliform cells within the adaxial leaf blade surface increased in the arl1 mutant. Bulk segregation analysis mapping in an F2 population derived from a single cross between arl1 and inbred line Gui18421 with normal leaves identified the arl1 locus on chromosome 2. Sequential fine-mapping delimited the arl1 locus to a 233.56-kb genomic interval containing three candidate genes. Sequence alignment between arl1 and Gui18421 identified an 8-bp insertion in the coding region of Zm00001eb082500, which led to a frame shift causing premature transcription termination in arl1 mutant. Meanwhile, both deep sequencing and Sanger sequencing showed that Zm00001eb082520 was present in Gui18421 but was absent in arl1. A pair of near isogenic lines (NILs) carrying the Gui18421 allele (NILGui18421) and the arl1 allele (NILarl1) were developed, and the leaves of NILarl1 plants had greater light transmission and photosynthetic rate in the middle and lower canopy than did those of NILGui18421 plants under high-density planting. Furthermore, NILarl1 had a higher seed setting rate, more kernels per ear, and an increased kernel weight per ear than NILGui18421, and the grain yield of NILarl1 was not affected as the planting density increased, suggesting that the arl1 locus can be used for genetic improvement of high-density planting tolerance. Taken together, the identification of arl1 and evaluation of yield-related traits for NILGui18421 and NILarl1 provide an excellent target for future maize improvement.

IntroductionTo increase the crop yield, the amount of agrochemicals used in field has increased in recent years. Moreover, indiscriminate use of chemical fertilizers has led to soil deterioration and compaction. Inclusion of straw and tillage practices to the field could play an important role in improving the soil quality and crop yield. Therefore, we hypothesized that combination of straw return and different tillage practices would result in improvement in soil health and crop productivity.MethodsTherefore an experiment was conducted a split plot design during 2018-2022. They were comprised of traditional planting with no straw return and straw return, accompanied by four different tillage methods: control (no tillage), rotary tillage (25 cm tillage depth), subsoiling (35 cm tillage depth), and subsoiling plus rotary tillage (35 + 25 cm tillage depth).ResultsResults showed that subsoiling along with rotary tillage enhanced soil total nitrogen (TN) by 9.0%, soil organic carbon (SOC) 7.5%, soil microbial biomass carbon (MBC) 6.8%, soil catalase (S-CAT) 9.6%, soil urease (S-UE) 4.1%, soil cellulase (S-CL) 14.5%, soil sucrase (S-SC) 10.8% and maize yield 3.0% compared to no tillage.DiscussionCorrelation analysis showed that (i) maize yield was significantly and positively correlated with S-SC, S-CL, S-UE, SOC, and TN. (ii) S-SC was significantly and positively correlated with TN, SOC, and MBC. (iii) TN was significantly and positively correlated with S-UE, and SOC was significantly and positively correlated with S-SC. It has been concluded that straw return coupled with subsoiling and rotary tillage is an appropriate approach to enrich soil nutrients, enzyme activities, and maize yield.

以桂单162为供试品种,采用大田试验,研究常规施肥(CK)、"一炮轰"和一次性缓控释肥(2 种)共4 个处理对春玉米农艺性状、干物质积累与分配、产量和经济效益的影响.结果表明:与常规施肥(CK)相比,一次性缓控释肥处理下玉米株高、穗位高、茎粗、叶面积和单株干物质积累量均较高;一次性缓控释肥处理下前期干物质在叶片和茎鞘中的分配比例均较低,后期在籽粒中的分配比例较高;一次性缓控释肥有助于增加玉米吐丝阶段穗的干物质积累量,提高成熟期玉米籽粒产量;一次性缓控释肥处理不仅能提高玉米百粒重,同时也能提高玉米穗行数和行粒数,穗长、穗粗和秃尖长均有不同程度的改善.T3 处理条件下,百粒重较CK提高 7.36％,秃尖长减少 28.8％,产量提高 3.96％,农民收益增长 25.20％.综之,与常规施肥相比,选用茂施牌一次性缓控释肥进行一次性底施,不仅可以为植株生长过程提供充足肥料,同时还可以合理调配干物质分布,增加籽粒中干物质分配比例,最终提高产量和收益.

通过测定不同老化程度玉米种子的发芽指标、幼苗形态指标和生理生化指标,研究玉米种子的生理生化、生命活力因人工老化而发生的变化,为玉米种子老化机制及种子活力修复研究奠定基础.以桂 081 和桂单 1622 个玉米品种为试验材料,采用高温高湿(48℃、相对湿度95%)的人工老化方法,研究人工老化对玉米种子发芽指标、幼苗形态指标、相对电导率、丙二醛含量和过氧化物酶活性等指标的影响.结果证实了逐步增加老化时长,除 2 个品种种子的丙二醛(MDA)含量、相对电导率同步上升之外,其余生理指标如过氧化物酶活性、发芽指数、发芽率、发芽势、活力指数等均同步下降,老化 10d时,桂单0810 和桂单 162 种子的发芽势、发芽率、发芽指数和活力指数分别比对照降低60.32%和62.54%、55.44%和62.68%、49.52%和54.33%、65.63%和70.00%,而MDA含量大幅升高 90.91%和93.20%,过氧化物酶活性分别降低 60.16%和 83.04%.相关性分析表明,MDA含量、过氧化物酶活性与种子活力的相关性达到极显著水平.人工老化方式对玉米种子进行处理能够显著抑制其活力,影响幼苗的生长.相对电导率、MDA 含量和 POD 活性可用于衡量玉米种子的活力水平,而且种子耐老化能力存在品种间差异,桂单 0810 耐老化能力高于桂单 162.

随着人们对健康食品的需求增加,全国鲜食玉米消费市场不断壮大.广西与东南亚各国接壤,有较多的经济贸易联系,在"一带一路"发展中有较多的机遇.广西在鲜食玉米育种及产业上发展很快,优势显著,从种质资源丰富及特色明显、自主创新能力提升、育种实力增强及审定品种数量增多、种植面积逐年攀升、产业发展的优势、产业链初具规模和示范效应等方面详细论述了广西鲜食玉米的产业优势.从"一带一路"沿线国家农业发展角度、经济发展角度、推广阻力的角度分析了广西鲜食玉米产业在"一带一路"发展中的机遇,为广西鲜食玉米育种及产业发展提供支撑.

玉米是世界上最重要的粮食作物之一,其种子质量的好坏直接影响粮食的产量,与食品生产安全息息相关,种子作为生产源头牵动着整个玉米产业链的发展.种子的质量还影响农作物的生存能力,是农业生产资料重要的组成部分.种子作为各种技术的关键载体,优质高产的种子对于提高食品安全和经济产量有着重要意义.随着农作物种子检测技术的不断进步,玉米的产量和质量得到有效提高.尤其是将近红外光谱分析技术应用在玉米种子检测中,使玉米种子检测质量与效果得到明显提高,为农户育种、种植及营销节省了成本,提高了经济效益.首先介绍了近红外光谱检测技术的应用原理,之后分析了近红外光谱分析技术的优缺点,最后探讨了近红外光谱分析技术在玉米种子检测中的应用.