In the cold and cool region of northeastern China, low temperature and limited soil moisture retention constrain maize yield, and mulching is widely used to alleviate these limitations. To reduce the environmental risks associated with polyethylene (PE) film, a two-year field experiment (2024-2025) was conducted to evaluate biodegradable films suitable for maize production in this region. Five mulching treatments were tested, including PE film (T1) and four biodegradable options-polypropylene carbonate (PPC, T2), polybutylene adipate terephthalate (PBAT, T3), polylactic acid (PLA, T4), and a PBAT + PPC composite film (T5)-with no mulching as the control (CK). Across two growing seasons, T1-T5 increased the effective grain filling duration by 4.74-13.58%, raised grain auxin content during grain filling by 1.54-29.33%, and increased the two-year mean yield by 13.95-24.73% compared with CK. Notably, the PBAT + PPC composite film (T5) did not differ significantly from PE film (T1) in grain filling traits, hormone regulation, or yield improvement (p > 0.05), indicating that T5 is a promising and sustainable alternative to PE film for maize production in cold regions. These findings provide technical support for selecting and applying biodegradable mulch films in cold-region maize systems and contribute to environmentally sustainable high-yield cultivation.

Spring maize production in cool regions of Northeast China is constrained by low temperatures, variable soil moisture, and limited thermal resources. A two-year field experiment was conducted in Dunhua, Jilin Province, China, in 2024 and 2025 to evaluate the growth, physiological performance, grain-filling characteristics, starch accumulation, and yield of six maize hybrids representing early-, medium–early-, and medium-maturing groups under biodegradable film mulching. Soil temperature and moisture content, photosynthetic traits, shoot dry matter accumulation, grain-filling parameters, starch synthase activity, starch content, and grain yield were measured. The medium–early-maturing group maintained higher net photosynthetic rate, stomatal conductance, and transpiration rate at the twelve-leaf stage (V12) and milk stage (R3) and accumulated more shoot dry matter at R3. Compared with the early-maturing group, the maximum grain-filling rate (Rmax), kernel weight at the maximum grain-filling rate (Wmax), and mean grain-filling rate (Vmean) increased by 10.0%, 12.1%, and 7.2%, respectively; compared with the medium-maturing group, the corresponding increases were 5.4%, 2.8%, and 9.0%, respectively. The medium–early-maturing group also maintained relatively high starch synthase activity and starch accumulation during the middle and late grain-filling stages. Averaged across the two years, grain yield was 20.0% and 9.1% higher than that of the early- and medium-maturing groups, respectively. Overall, the medium–early-maturing group achieved better coordination among canopy photosynthesis, dry matter accumulation, grain filling, and starch synthesis and showed better adaptation to the thermal conditions of this agroecological region, where the annual effective accumulated temperature is approximately 2300–2400 °C·d. Therefore, the medium–early-maturing group may represent a suitable option for achieving high yield under biodegradable film mulching in this region.

An appropriate drip irrigation amount and the straw return method are important ways to save water and achieve efficient maize production in semi-arid areas. A 2-year controlled field plot experiment was performed with two factors: straw return (straw removal, straw mulching) and differing drip irrigation amounts (200, 350, and 500 mm). Changes in growth, development, photosynthesis, yield, the components, and the water-use characteristics of maize under the intercropping conditions of drip irrigation amount and straw return were studied. The results showed that an increase in drip irrigation favored an increase in the net photosynthetic rate (Pn), stomatal conductance (Gs), and intercellular carbon dioxide concentration (Ci) of maize, and promoted an increase in maize plant height and leaf area index, which resulted in the accumulation of more dry matter and increased the maize yield. Compared with straw removal, straw mulching maintained a higher photosynthetic capacity at the later stages of maize growth and development under irrigations of 200 and 350 mm; the average increase in Pn over two years ranged from 4.06 to 19.19%; and good plant growth was maintained, thereby leading to the accumulation of more dry matter, with the average increase over two years ranging from 0.51 to 27.22%. Straw mulching also significantly improved water-use efficiency (WUE) at 350 mm of irrigation, with the average increase in yield over two years ranging from 4.58 to 4.83%. Overall, straw mulching had a positive impact on maize when irrigation was low, and when it was high, straw mulching did not adversely affect maize. Therefore, irrigation combined with straw mulching technology may be used to improve maize yield and WUE in semi-arid areas of Jilin Province.

Returning straw to the field can increase soil organic matter content, improve soil physical and chemical properties, enhance soil biological activity, and thus improve soil fertility. However, returning straw to the field has problems such as slow decomposition rate and delayed nutrient release. Reasonable water management is one of the important measures to improve the effectiveness of returning maize straw to the field. To explore soil moisture management measures suitable for maize straw decomposition, nitrogen release, maize yield increase, and efficient water utilization, a 2-year study was conducted in a movable rain shelter. Set three irrigation quotas, namely 200 mm, 350 mm, and 500 mm (represented by I 200, I 350, and I 500), and two straw return methods, straw returning and not returning to the field were represented by SR and CK, respectively. The experimental results showed that the decomposition rate and nitrogen release rate of I 350 were significantly greater than those under the other irrigation treatments. There was no significant difference in plant nitrogen uptake or maize yield between I 350 and I 500, but the values were significantly greater than those in I 200. The water use efficiency of I 350 treatment group was significantly greater than that of I 500 treatment group. Returning straw to the field has only a compensatory effect on the nitrogen uptake and transport of plants under some low irrigation levels. Under these experimental conditions, I 350 was more conducive to straw decomposition, straw nitrogen release, maize nitrogen uptake, maize yield increase, and efficient water use. This study can provide a theoretical reference for soil moisture management under straw return conditions in semi-arid areas of Jilin Province, China.

Optimizing drip irrigation with straw mulch return represents a promising sustainable intensification strategy for revolutionizing regional water management. This 2-year controlled field experiment examined straw incorporation effects (removal and return) and drip irrigation levels (200, 350, 500 mm) on maize carbon-nitrogen metabolism, root bleeding sap characteristics, dry matter accumulation, and yield. Dry matter and yield increased with irrigation amount. Under 200-350 mm irrigation, straw return enhanced root bleeding intensity; elevated nitrogen, phosphorus, potassium, calcium, and magnesium concentrations in bleeding sap; and promoted soluble sugar and hydrolyzed amino acid contents, establishing material foundations for yield formation. Straw mulching increased cytokinin while reducing abscisic acid content, delaying senescence. Leaf activities of nitrate reductase, glutamine synthetase, ribulose-1,5-bisphosphate carboxylase/oxygenase, and phosphoenolpyruvate carboxylase significantly increased under straw return, enhancing photosynthesis and improving 100-grain weight, ear length, ear diameter, and yield while decreasing bald tip length. Low irrigation amplified straw return benefits on maize growth and metabolism, whereas high irrigation negated these effects. Therefore, combining drip irrigation with straw return provides scientific foundations for water resource management in Jilin Province and theoretical bases for sustainable agricultural development in water-limited regions.

【Background】Maize production in Jilin province of China needs irrigation because precipitation and antecedent soil water in its growth season cannot meet its demand. Although the impact of water stress in maize growth has been well documented, how its physiological characteristics respond to irrigation amount is an issue remaining obscure for maize production in Jilin province. 【Objective】This paper aims to elucidate irrigation-water use efficiency of the maize under different irrigation amounts, with a view to improve water use efficiency without compromising yield in the semi-arid areas in the west of the province. 【Method】A two-year field experiment was conducted with the variety Huanong 887 as the model plant. We compared four irrigation amounts: 500 (CK), 900 (Q1), 1 700 (Q2) and 2 500 m3/hm2 (Q3), and in each treatment we measured the accumulation of nitrogen, grain filling, activities of nitrogen metabolizing enzymes in leaves, as well as root injury level. 【Result】①The average grain-filling rate, 100-grain weight and root injury level all increased with the irrigation amount, but their values in Q2 and Q3 were significantly higher than those in Q1 and CK. ②Compared to Q1 and CK, Q2 and Q3 significantly increased nitrogen content in grains, stems and leaves. ③With the increase in irrigation amount, the activities of glutamine synthetase (GS) in the leaves increased, while the activities of glutamate dehydrogenase (GDH) in the leaves decreased. ④The yield increased with irrigation amount, especially in Q2 and Q3. ⑤No significant difference in yield and physiological traits was found between Q2 and Q3. 【Conclusion】Soil moisture is an important factor limiting growth and development of maize in the semi-arid areas in the western Jilin province. With the increase in irrigation amount, the yield, average grain-filling rate, 100-grain weight, root injury level, nitrogen accumulation and GS activity in the leaves all increased, while the activity of GDH in the leaves decreased. The physiological traits were significantly correlated with the yield. When the irrigation amount was 1 700 m3/hm2, the grain-filling rate, root injury level, nitrogen accumulation, nitrogen metabolizing enzyme activity in the leaves were optimal, giving the highest yield. It thus can be used as the reference irrigation strategy for maize production for the studied areas.

In order to explore the cultivation techniques for increasing maize yield and water efficient utilization in the semi-arid area of Jilin Province, China, a field experiment was carried out in Taonan City, the semi-arid area of Jilin Province in 2020 and 2021. Common plastic film mulching (CM), degradable plastic film mulching (DM), crushed straw mulching (SM) and no mulching (CK) were set up to study the effects of surface mulching on the temporal and spatial changes of soil water and temperature, physiological characteristics of maize, maize yield and water use efficiency. The results showed that the soil water content was related to rainfall and its spatial and temporal distribution in maize growth stage. The soil water content in 0–60 cm increased with the increase of soil depth in the vertical direction, and the soil water content between treatments was SM > CM > DM > CK. The soil temperature increased first and then decreased with the growth process of maize, and gradually decreased with the deepening of the plough layer. The temperature was increased by plastic film mulching (CM > DM), and decreased by straw mulching. Different water temperature effects caused by surface mulching have different effects on the physiological characteristics, growth and yield of maize, and DM treatment was the best. DM treatment significantly increased the bleeding sap mass and cytokinin content of maize roots due to its coordinated water temperature, significantly reduced the content of soluble sugar and abscisic acid in bleeding sap compared with CK, transmitted the physiological reaction of roots upward through plant hormones and other information substances, indirectly affected the physiological and biochemical processes of shoots, and enhanced the activities of ribulose diphosphate carboxylase, phosphoenolpyruvate carboxylase and glutamine synthetase in leaves, it improved the photosynthetic performance of maize leaves, promoted the growth and development of maize and the accumulation of dry matter in each period, thereby significantly increasing maize yield by 14.13

[目的]本研究旨在探寻玉米对不同滴灌模式的生理响应机制,寻求滴灌方式与滴灌定额之间的优化方案,为半干旱区玉米节水高效生产提供理论依据.[方法]利用可移动式防雨棚进行2年的小区试验,以玉米品种'富民985'为试验材料,设置地上滴灌与浅埋滴灌2种滴灌方式,玉米全生育期300、400和500 mm 3个滴灌定额,即地上滴灌-300 mm(T1)、地上滴灌-400 mm(T2)、地上滴灌-500 mm(T3)、浅埋滴灌-300 mm(T4)、浅埋滴灌-400 mm(T5)和浅埋滴灌-500 mm(T6)6个处理,研究不同滴灌模式对玉米光合特性、叶绿素荧光特性、叶片氮代谢酶活性及根系伤流强度的影响.[结果]与T1、T2和T4处理相比,T3、T5和T6处理玉米大喇叭口期(V12)、吐丝期(R1)和灌浆期(R3)叶片的净光合速率(Pn)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)、蒸腾速率(Tr)、水分利用效率(WUE)、表观叶肉导度(AMC)、光系统Ⅱ最大光合效率(Fv/Fm)、光系统Ⅱ实际光合效率(ΦPSⅡ)、电子传递效率(ETR)、光化学淬灭系数(qP)增加,气孔限制百分率(Ls)和非光化学猝灭系数(NPQ)下降.不同滴灌模式条件下,T3、T5和T6处理玉米叶片的谷氨酰胺合成酶(GS)活性、根系伤流强度均呈增加趋势,且显著高于T1、T2和T4处理,但谷氨酸脱氢酶(GDH)活性呈下降趋势.[结论]采用浅埋滴灌-全生育期400 mm滴灌定额(T5处理)的滴灌模式的玉米在根系伤流强度、叶片氮代谢酶活性、光合特性、叶绿素荧光特性等方面均表现较佳,获得了节水与高产的双重目的.

Drip irrigation has a close relationship with the growth and development of maize grains and yield formation in semiarid areas. To explore the response mechanism of grain yield formation to drip irrigation quotas, a 2-year pond planting experiment was conducted under controlled conditions, by using two maize varieties with differences in drought resistance as experimental materials. Six treatments were set up, including CK1 (drought-resistant variety, 500 mm), T1 (drought-resistant variety, 350 mm), T2 (drought-resistant variety, 200 mm), CK2 (drought-sensitive variety, 500 mm), T3 (drought-sensitive variety, 350 mm), and T4 (drought-sensitive variety, 200 mm). The changes in maize grain filling characteristics, related hormones, enzyme activity related to starch synthesis, sugars and amino acids contents, and yield were analysed. The results showed that 100-grain weight at different filling times, filling rate, average filling rate, auxin, cytokinin, acid sucrose invertase, sucrose synthase, starch synthase, and adenosine diphosphate glucose pyro phosphorylase activities in maize grains decreased and the abscisic acid content and content of various amino acids and sugars in grains increased with the decrease in drip irrigation quota. The percentage of changes in drought-sensitive maize varieties was relatively high. The maize yield decreased with the decrease in drip irrigation quota. In summary, there was no significant difference in grain filling characteristics, hormone content, starch synthesis enzyme activity, and yield between maize treated with T1 (drought-resistant variety, 350 mm) and the control treatment. This effectively maintained grain growth and yield formation, achieving the goal of water saving and stable yields.

为探究不同地膜覆盖对吉林省东部冷凉区玉米根系伤流液中含氮物含量和强度的影响,2019年在吉林省安图县松江镇南道村(42°32′N,128°24'E)进行田间试验,以'大德216'玉米品种为试验材料,设透明可降解地膜覆盖(D1)、透明不可降解地膜覆盖(D2)、黑色不可降解地膜覆盖(D3)和无地膜覆盖(D0)处理,分别于播种后50、65、90和105 d取根系伤流液,于实验室测定其硝态氮、氨态氮、游离氨基酸和可溶性蛋白含量,分析不同地膜覆盖下玉米根系伤流液中含氮物质含量和强度与产量的相关性.结果表明:两种透明地膜覆盖玉米产量显著高于无地膜覆盖和黑色地膜覆盖处理;地膜覆盖能显著增强玉米生长前期根伤流强度和伤流液中铵态氮、游离氨基酸、可溶性蛋白以及总含氮物质含量及强度,两种透明地膜覆盖比黑色地膜覆盖效果更显著;两种透明地膜覆盖下伤流液中总含氮物质强度比无地膜覆盖的提升了 4.7倍,相比黑色地膜覆盖增加1.1倍;玉米生长前期根伤流强度和伤流液中总含氮物质强度与产量皆呈极显著正相关关系,相关系数达0.84～0.98.这说明冷凉区地膜覆盖能有效增加玉米根系吸收与代谢水平,其中以可降解透明地膜覆盖效果最佳.研究结果为其产量形成提供了物质基础.

研究合理的秸秆覆盖耕种模式是实现半干旱区秸秆覆盖条件下玉米绿色高效生产的重要途径.开展2a大田试验,设置传统耕作模式(CK)、秸秆覆盖模式(T1)、秸秆覆盖+深松模式(T2)、秸秆覆盖+碎混模式(T3)4 个处理,研究不同秸秆覆盖耕种模式对玉米根系伤流特性、光合特性、碳氮代谢相关酶活性、生长发育、产量及其构成因素和水分利用特性的影响.结果表明:不同处理玉米根系伤流强度、伤流液中细胞分裂素(CTK)和生长素(IAA)含量均表现为T3>T2>CK>T1,脱落酸(ABA)含量表现为T1>CK>T2>T3;与CK和T1 处理相比,T2 与T3 处理的CTK和IAA含量显著增加、ABA含量显著下降.玉米叶片净光合速率(Pn)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)、蒸腾速率(Tr)、表观叶肉导度(AMC)和叶片水分利用效率(WUEL)均表现为T3>T2>CK>T1,气孔限制百分率(Ls)表现为T3

Revealing the mechanism underlying the responses of maize to different drip irrigation modes can provide a theoretical basis for water saving and efficient maize production. During 2020 and 2021, an experiment was carried out in movable rainproof sheds in Jilin semi-arid area. Six treatments were set, including L1（ridge drip irrigation, 300 mm）, L2（ridge drip irrigation, 400 mm）, L3（ridge drip irrigation, 500 mm）, Q1（shallow buried drip irrigation, 300 mm）, Q2（shallow buried drip irrigation, 400 mm）, and Q3（shallow buried drip irrigation, 500 mm）. We examined the effects of different drip irrigation modes on photosynthetic variables, growth and development, yield and water use characteristics of maize. The results showed that net photosynthetic rate（P n ） of Q2, Q3, and L3 treatments was significantly higher than that of L1, L2, and Q1 treatments at the same light quantum density, when the optical quantum density exceeded 400 μmol·m -2 ·s -1 . The apparent quantum efficiency, light saturation point, dark respiration rate, and maximum net photosynthetic rate at light saturation point of L3, Q2 and Q3 treatments were significantly higher than those of L1, L2 and Q1 treatments at flowering stage and filling stage. The P n of L1, Q1, and L2 treatments was significantly lower than that of L3, Q2, and Q3 treatments at the same CO 2 concentration when it exceeded 200 μmol·mol -1 . The CO 2 compensation point, CO 2 saturation point, maximum net photosynthetic rate, Rubisco maximum carboxylation efficiency, propyl phosphate utilization and maximum electron transfer rate of L3, Q2, and Q3 treatments were significantly higher than those of L1, L2, and Q1 treatments. The grain yield, 100-grain weight, ear length, number of grains per ear, dry matter mass and leaf area index of L3, Q2, and Q3 treatments at different growth stages were significantly higher than those of L1, L2, and Q1 treatments. There was no difference in the photosynthetic response parameters, growth, and yield formation of maize leaves among L3, Q2 and Q3 treatments. Water use efficiency of Q2 treatment was significantly higher than that of the other five treatments. In conclusion, the Q2 treatment showed better photosynthetic response characteristics, growth and development, yield formation and water use, which realized yield increase and high water efficiency. This study provides a reference for the efficient production of maize and the formulation of irrigation schedule when shallow drip irrigation technology is applied in the semi-arid area of Jilin Province.

To explore water efficient cultivation technology and improve maize yield in semi-arid area of Jilin Province, a four-year experiment was carried out with different mulching materials. Four treatments included no mulching（CK）, common plastic film mulching（CM）, degradable plastic film mulching（DM） and straw mulching（SM）. The effects of different mulching treatments on soil moisture, soil temperature, maize growth and development, yield and water use efficiency were studied. The results showed that the temporal and spatial variation of soil water storage during maize growth period was related to the temporal and spatial distribution of rainfall in that year. The soil water storage in 20～60 cm vertical space was significantly higher than that in 0～20 cm, and the soil water storage of different treatments was SM＞CM＞DM＞CK. The soil temperature of 0～20 cm in the cultivated layer increased first and then decreased with the growth period of maize, and gradually decreased with the increase of soil depth. The decreasing range was CM＞SM＞DM＞CK. Compared with CK, CM and DM increased the ground temperature by 2.12℃, 1.71℃ and 2.07℃, 1.52℃ respectively in May and June, while SM decreased by 1.72℃, 1.01℃. Compared with the temperature in May and June, the daily ground temperature of plastic film mulching increased by 2.2～3.2℃, and that of straw mulching decreased by 0.3～0.6℃. The decline range of ground temperature of mulching in August and September was lower than that of air temperature. The average yield of CM and DM increased by 8.59% and 14.10%, that of SM decreased by 8.96%, the water use efficiency of CM and DM increased by 10.3% and 15.6%, and the straw mulching decreased by 8.4%. Maize yield was significantly positively correlated with soil temperature in soil layer 5 cm, 10 cm, 15 cm and 20 cm during May, June, August and September, and negatively correlated with soil water storage in soil layer 0～20 cm and R1. Degradable plastic film mulching has multiple functions such as moisture conservation, temperature rise, yield increase, water efficiency and environmental protection. It can be popularized in the cultivation of water efficient maize yield in semi-arid area.

研究土壤水分、玉米光合特性及产量对秸秆不同还田耕作技术的响应,为半湿润区水分、光能高效利用及玉米增产栽培模式提供理论依据.2018和2019年,采用秸秆还田和土壤耕作相结合的方法,设置秸秆离田旋耕起垄(CK)、秸秆深翻还田(SP)、免耕秸秆覆盖还田(SC)、秸秆覆盖深松(SS)4个处理.研究结果表明,2018和2019年各生育时期土壤含水率、叶面积指数、叶片的Pn、Gs、Ci和Tr,SS处理均显著高于CK处理.与CK相比,SS、SP、SC处理2018和2019年的玉米产量分别增加13.88％和14.82％、7.59％和9.12％、7.42％和8.5％.秸秆条带覆盖深松技术适合作为半湿润区水分、光能高效利用和玉米增产的一种优化栽培技术进行推广应用.

Accurate estimation of maize (Zea mays L.) straw production and exploration of appropriate straw return rate have important reference for guiding the comprehensive utilization of crop straw. In this study, we estimated the maize straw production (including aboveground straw and root straw) in recent ten years (2009–2018) of the four largest maize growing regions across China using the latest obtained region-specific maize straw index and root-shoot ratio and then determined the appropriate straw return rate of different regions based on the carbon (C) balance between straw C input and the total C emissions generated in maize cultivation. Our results showed that there were significant differences in maize straw index (MSI) and root-shoot ratio between different maize growing regions in China with spatial distribution trends of Huanghuaihai (HM) > North (NM) > Southwest (SW) > Northwest (NW) maize regions and SW > NW > NM > HM, respectively. On average, in the recent ten years, the total maize straw production of the four major regions was 216.03 Mt yr−1, including 192.73 Mt yr−1 for the aboveground straw production and 23.30 Mt yr−1 for root straw production. Nationally, when the maize straw return rate was 70.4% (45.8%, 57.4%, 62.2% and 84.5% in SW, HM, NW and NM respectively), the straw C input into soil can theoretically counterbalance the total C emission generated in maize cultivation. Additionally, the total soil organic C sequestration increased from 11.26 to 18.88 Mt C yr−1 for the whole four regions under the scenarios of 0%, 25%, 50%, 75% and 100% maize straw return.

灌溉是维持半干旱区作物生产的重要措施,节水灌溉技术因各国国情、地理和气候条件的不同会有所差异,发展节水灌溉是未来农业灌溉的前进方向,是迈向精准农业、智慧农业的必经之路.干旱与半干旱地区的农作物生长发育受灌溉因素影响较大,了解作物应对灌溉的生理响应机制可改善灌溉条件下作物的生长发育状况,为灌溉条件下作物产量的形成奠定基础.从国内外的农业灌溉现状出发,总结了近年来农业灌溉对作物产量形成特性、养分的积累与转运特性和生理特性的影响,为农业灌溉和作物在灌溉条件下的生理响应机制研究提供理论依据.

为探究半干旱区优化栽培模式下玉米籽粒形成及叶片对光与CO2的响应机制,进行2 a的大田试验,设置对照模式(CK)、农户习惯模式(T1)和优化栽培模式(T2)3种栽培模式,研究不同栽培模式对玉米籽粒灌浆特性、产量形成、叶片光合响应曲线及相关参数的影响.结果表明:T2处理在吐丝后各生育阶段的百粒质量和平均灌浆速率均显著高于T1和CK处理,与CK和T1处理相比,T2处理的2 a平均灌浆速率分别增加了31.58％、18.00％和30.77％、9.80％,T2处理的灌浆速率在吐丝后20～30 d达到最大值,并显著高于T1和CK处理,与CK和T1处理相比,2 a分别增加33.91％、10.04％和26.28％、14.99％;T2处理的产量显著高于T1和CK处理,与T1处理相比,2 a分别增加了15.67％和14.03％;3个处理玉米叶片的净光合速率随光照强度增加而增加,当光量子密度超过300μmol?m-2?s-1时,T2处理的净光合速率要显著高于T1与CK处理;随着生育时期的推进,T2处理的光补偿点量子效率(AQE)显著高于T1与CK处理,在灌浆期(R3)降至3个生育时期(V12、R1、R3)间的最低值;T2处理的光补偿点(LCP)和光饱和点(LSP)均显著高于T1与CK处理,T2处理LSP与LCP的差值均为最大,2 a 3个生育时期(V12、R1、R3)分别达到1871.6、1914.4、1891.9μmol?m-2和1909.7、1848.6、1822.4μmol?m-2?s-1;CO2补偿点(CCP)、CO2饱和点(CSP)、CO2饱和时最大净光合速率(CSPn)和羧化效率(CE)均呈T2>T1>CK,T1与T2处理的CCP均显著高于CK处理,T2处理的CSP均显著高于T1与CK处理,T2处理CSP与CCP的差值更大,2 a 3个生育时期(V12、R1、R3)分别达到540.06、558.87、561.19μmol?m-2和539.13、518.54、574.73μmol?mol-1;T2处理的CE在R1和R3期均显著高于T1和CK处理;T1与T2处理的Rubisco最大羧化效率(Vcmax)、最大电子传递速率(Jmax)和磷酸丙糖利用率(TPU)均显著高于CK处理.综上所述,优化栽培模式(T2处理)可维持叶片的光合作用能力,促进玉米利用弱光进行光合作用,增加玉米对光和CO2的适应范围,从而增加光合产物的转运能力和叶片的固碳羧化能力,促进籽粒灌浆,减少资源利用的同时实现玉米产量提高,适合在吉林省西部半干旱区进行推广应用.

为探明冷凉区地膜覆盖对玉米干物质积累、分配及运转和对氮素积累的影响,以玉米品种大德216为材料,在吉林省安图县进行田间试验,设置透明可降解地膜覆盖(T1)、透明不可降解地膜覆盖(T2)、黑色不可降解地膜覆盖(T3)和无膜(TCK)处理,测定干物质、氮素积累量及产量.结果表明,不同地膜覆盖均能显著提高玉米产量,其中T1和T2处理的产量显著高于T3处理.3种地膜覆盖均能显著增加玉米干物质积累,在播种后65、90、105和140d,T1和T2处理的干物质积累均显著高于T3处理.不同覆膜处理在播种后65～90d积累量最多,3种覆膜处理条件下的氮素积累均显著高于TCK处理,成熟期各器官氮素积累分配比例表现为籽粒＞叶＞茎＞鞘＞雄穗.综上,地膜覆盖可提高玉米干物质积累量,优化物质运转分配,促进玉米氮素积累,提高玉米产量,透明覆膜栽培可有效改善冷凉区积温不足、只能种植早熟品种的局限性,拓宽品种选择范围.透明可降解地膜为冷凉区玉米最佳抗逆丰产栽培模式.

以迪卡159为供试材料,设置6.0×104(D1)、7.0×104(D2)、8.0×104(D3)和9.0×104株/hm2(D4)4个密度水平,在8展叶期喷施化控剂玉多十(HK)和清水为对照(CK)2个处理,研究不同种植密度与化学调控技术对植株茎秆性状的影响.结果表明,随种植密度的增大,迪卡159的株高、穗位高显著增高,茎秆节间长变长,茎粗变小,扁率增大,茎秆强度变弱.HK处理后,株高、穗位高显著降低,4～5节位节间长大幅度减少,茎粗增加,扁率降低,茎秆强度增强,茎秆横折强度与穿刺强度在3个时期均随种植密度的上升呈现整体下降趋势,并于乳熟期达到最大值.HK处理后,茎秆的横折强度与穿刺强度增强,其中,4～5节位提升幅度最大.HK处理增加了灌浆期与乳熟期第3节位的木质素与纤维素含量,D1、D2、D4密度下效果显著.倒伏率随种植密度的升高呈上升趋势;HK处理可以显著降低倒伏率,4个密度下分别比对照降低了 26.15％、47.72％、35.17％和33.82％.

吉林省对国家粮食安全作出了突出贡献,并且拥有较大的持续增产潜力.文章分析并指出影响粮食产量的根本因素是土地质量和种业发展水平,从强化黑土地保护与利用、加速现代种业发展、创新粮食安全保障机制等方面对吉林省进一步提升农业综合生产能力,持续增强对国家粮食安全的保障能力提出了建议.