Soil mineral nitrogen and yield-scaled soil N2O emissions lowered by reducing nitrogen application and intercropping with soybean for sweet maize production in southern China

The increasing demand for fresh sweet maize （Zea mays L. saccharata） in southern China has prioritized the need to find solutions to the environmental pollution caused by its continuous production and high inputs of chemical nitrogen fertilizers. A promising method for improving crop production and environmental conditions is to intercrop sweet maize with legumes. Here, a three-year field experiment was conducted to assess the influence of four different cropping systems （sole sweet maize （SS）, sole soybean （SB）, two rows sweet maize-three rows soybean （S2B3） intercropping, and two rows sweet maize-four rows soybean （S2B4） intercropping）, together with two rates of N fertilizer application （300 and 360 kg N ha-1） on grain yield, residual soil mineral N, and soil N2O emissions in southern China. Results showed that in most case, inter- cropping achieved yield advantages （total land equivalent ratio （TLER=0.87-1.25） was above one）. Moreover, intercropping resulted in 39.8% less soil mineral N than SS at the time of crop harvest, averaged over six seasons （spring and autumn in each of the three years of the field experiment）. Generally, intercropping and reduced-N application （300 kg N ha-1） produced lower cumulative soil N20 and yield-scaled soil N20 emissions than SS and conventionaI-N application （360 kg N ha-l）, respectively. $2B4 intercropping with reduced-N rate （300 kg N ha-~） showed the lowest cumulative soil N20 （mean value=0.61 kg ha-1） and yield-scaled soil N20 （mean value=0.04 kg t-1） emissions. Overall, intercropping with reduced-N rate maintained sweet maize production, while also reducing environmental impacts. The system of S2B4 intercropping with reduced-N rate may be the most sustainable and environmentally friendly cropping system.

Maize-soybean strip intercropping： Achieved a balance between high productivity and sustainability

Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus, and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability.

Suitability of the DNDC model to simulate yield production and nitrogen uptake for maize and soybean intercropping in the North China Plain

Intercropping is an important agronomic practice. However, assessment of intercropping systems using field experiments is often limited by time and cost. In this study, the suitability of using the DeNitrification DeComposition(DNDC) model to simulate intercropping of maize(Zea mays L.) and soybean(Glycine max L.) and its aftereffect on the succeeding wheat(Triticum aestivum L.) crop was tested in the North China Plain. First, the model was calibrated and corroborated to simulate crop yield and nitrogen(N) uptake based on a field experiment with a typical double cropping system. With a wheat crop in winter, the experiment included five treatments in summer: maize monoculture, soybean monoculture, intercropping of maize and soybean with no N topdressing to maize(N0), intercropping of maize and soybean with 75 kg N ha–1topdressing to maize(N75), and intercropping of maize and soybean with 180 kg N ha–1topdressing to maize(N180). All treatments had 45 kg N ha–1as basal fertilizer. After calibration and corroboration, DNDC was used to simulate long-term(1955 to 2012) treatment effects on yield. Results showed that DNDC could stringently capture the yield and N uptake of the intercropping system under all N management scenarios, though it tended to underestimate wheat yield and N uptake under N0 and N75. Long-term simulation results showed that N75 led to the highest maize and soybean yields per unit planting area among all treatments, increasing maize yield by 59% and soybean yield by 24%, resulting in a land utilization rate 42% higher than monoculture. The results suggest a high potential to promote soybean production by intercropping soybean with maize in the North China Plain, which will help to meet the large national demand for soybean.

Effects of maize-soybean relay intercropping on crop nutrient uptake and soil bacterial community

Maize-soybean relay intercropping is an effective approach to improve the crop yield and nutrient use efficiency,which is widely practiced by farmers in southwest of China.To elucidate the characteristics of different planting patterns on crop nutrient uptake,soil chemical properties,and soil bacteria community in maize-soybean relay intercropping systems,we conducted a field experiment in 2015–2016 with single factor treatments,including monoculture maize(MM),monoculture soybean(MS),maize-soybean relay intercropping(IMS),and fallow(CK).The results showed that the N uptake of maize grain increased in IMS compared with MM.Compared with MS,the yield and uptake of N,P,and K of soybean grain were increased by 25.5,24.4,9.6,and 22.4%in IMS,respectively,while the N and K uptakes in soybean straw were decreased in IMS.The soil total nitrogen,available phosphorus,and soil organic matter contents were significantly higher in IMS than those of the corresponding monocultures and CK.Moreover,the soil protease,soil urease,and soil nitrate reductase activities in IMS were higher than those of the corresponding monocultures and CK.The phyla Proteobacteria,Acidobacteria,Chloroflexi,and Actinobacteria dominated in all treatments.Shannon’s index in IMS was higher than that of the corresponding monocultures and CK.The phylum Proteobacteria proportion was positively correlated with maize soil organic matter and soybean soil total nitrogen content,respectively.These results indicated that the belowground interactions increased the crop nutrient(N and P)uptake and soil bacterial community diversity,both of which contributed to improved soil nutrient management for legume-cereal relay intercropping systems.

Relay-intercropping soybean with maize maintains soil fertility and increases nitrogen recovery efficiency by reducing nitrogen input

Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.

Effects of Different Planting Pattern of Maize (<i>Zea mays</i>L.) and Soybean (<i>Glycine max</i>(L.) Merrill) Intercropping in Resource Consumption on Fodder Yield, and Silage Quality

An experiment was carried out at the field units of the north campus experimental areas in Northwest Agriculture and Forestry University, Yangling, Shaanxi Province, P. R. China. The experiment was conducted on summer season (June to September) to determine the effects of different planting patterns of maize and soybean intercropping in resource consumption on fodder yield and silage quality. The main treatments were one sole crop of maize (SM) and four maize-soybean intercropping patterns (1 row maize to 1 row soybean (1M1S), 1 row maize to 2 rows soybean (1M2S), 1 rows maize to 3 rows soybean (1M3S) and 2 rows maize to 1 row soybean (2M1S), respectively. The experiment was a randomized complete block design with three replications, and plot size of 12 m by 5 m. The crops were harvested when the maize reached at milk stage and soybean at R7 stage. The result indicated significant increase in fresh biomass and dry matter production of maize fodder alone as compared to maize intercropped with soybean fodder. It was correlated with a higher consumption of environmental resources, such as photosynthetically active radiation (PAR) and soil moisture by intercropping. After 45 days of ensiling period, silage samples were analyzed for pH, organic acids (Lactic, acetic, and butyric), dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF), calcium (Ca), sodium (Na), phosphorus (P), magnesium (Mg), and potassium (K). It was concluded that in all intercropped silages, crude protein (CP) values were higher (1M1S, 12.1%;1M2S, 12.2%;1M3S, 12.4%;2M1S, 12.1%) than the monocrop maize (SM, 8.7%) silage. Higher organic acids (p < 0.05) were produced in the 1M3S silages as compared to others silages. The study indicated that among all intercropped silages, the 1M3S (1 row maize to 3 rows soybean) was preferable according to nutrient composition than other intercropped silages.

Image-based root phenotyping for field-grown crops:An example under maize/soybean intercropping

Root architecture,which determines the water and nutrient uptake ability of crops,is highly plastic in response to soil environmental changes and different cultivation patterns.Root phenotyping for field-grown crops,especially topological trait extraction,is rarely performed.In this study,an image-based semi-automatic root phenotyping method for field-grown crops was developed.The method consisted of image acquisition,image denoising and segmentation,trait extraction and data analysis.Five global traits and 40 local traits were extracted with this method.A good consistency in 1st-order lateral root branching was observed between the visually counted values and the values extracted using the developed method,with R^(2)=0.97.Using the method,we found that the interspecific advantages for maize mainly occurred within 5 cm from the root base in the nodal roots of the 5th-7th nodes,and that the obvious inhibition of soybean was mostly reflected within 20 cm from the root base.Our study provides a novel approach with high-throughput and high-accuracy for field research on root morphology and branching features.It could be applied to the 3D reconstruction of field-grown root system architecture to improve the inputs to data-driven models(e.g.,OpenSimRoot)that simulate root growth,solute transport and water uptake.

Effect of Intercropping Ginger and Sweet Maize on Growth,Yield and Benefits

Ginger is an important cash crop in Shandong Province and it usually takes the sole cropping in the production.In order to explore new ginger cultivation patterns and improve planting benefits,sweet maize(Jingengtian 1)was intercropped with ginger(Laiwu ginger).The plug seedling was performed for sweet maize on April 18.Ginger was planted with plastic film mulching on April 20,and double-row sweet maize seedlings were transplanted on the ridges of interlaced ginger fields on May 2.The sweet maize was harvested from July 18 to 25,and the tillering rate of sweet maize reached 100%.The number of tillers in intercropping was more than that of sole cropping,and the highest average tiller reached 5.32 per plant;when sweet maize was intercropped,the number of ears decreased by 17.35%and the ear weight decreased by 8.07%.Ginger was harvested on October 20,the number of branches of intercropping ginger decreased by 5.12%to 6.47%,and the rhizomes weight per plant decreased by 5.64%to 16.43%.The economic benefit of ginger intercropping sweet maize was higher than that of sole ginger cropping.The intercropping model increased the efficiency by 6.28%and 2.87%respectively in the two bases,and increased the net income by 12000 and 5000 yuan/ha,respectively.

滴灌下氮肥减量配施生物炭对玉米大豆间作系统光合特性和产量的影响

为研究氮肥减量结合生物炭对玉米大豆间作群体光合特性和产量的影响,设置不同种植模式(玉米单作、大豆单作、玉米大豆间作)、生物炭(2,4,6 t·hm^(-2))、氮肥减量(165,210,255 kg·hm^(-2))三因素试验,采用正交试验设计方法,探讨不同种植模式氮肥减量配施生物炭的适宜用量。结果表明:单作与间作模式玉米适宜的用量分别为氮肥210与255 kg·hm^(-2),生物炭用量均为4 t·hm^(-2)。间作系统产量达到13395 kg·hm^(-2),较单作玉米下降20.13%,间作玉米、大豆较相应单作产量分别下降35.69%和56.39%,有效株数低是导致间作玉米产量下降的主要原因,而单位面积株数与单株粒数的合理调控是决定间作大豆产量高低的关键因素。间作处理IN3C2(氮肥225 kg·hm^(-2)、生物炭4 t·hm^(-2))玉米的Pn从大口期到灌浆期持续升高,在灌浆期达到峰值,大豆从开花期经历结荚期到鼓粒期持续升高,在鼓粒期达到峰值,较其它处理具有显著光合优势,且大豆在结荚期和鼓粒期表现显著的边际优势。综上,滴灌下,氮肥减量与生物炭配施,单作和间作玉米较优的氮肥用量分别为210和255 kg·hm^(-2),生物炭为4 t·hm^(-2)。

玉米大豆间作干物质积累和氮磷吸收利用的边际效应

【目的】研究间作对玉米大豆干物质积累及氮磷吸收利用特性的影响机制,对实现玉米、大豆间作高产高效具有重要指导意义。【方法】试验设玉米单作、大豆单作、玉米大豆间作3种种植方式,分别测定玉米大口期、吐丝期和成熟期的植株氮磷积累量和大豆开花期、结荚期和成熟期的植株氮磷积累量,研究间作对玉米、大豆不同器官干物质积累及氮磷吸收积累特性,明确氮磷吸收利用的边际效应。【结果】与单作相比,间作降低了玉米干物质和氮磷的积累,促进了根系吸收氮向籽粒的分配;降低了大豆干物质积累,尤其对中行的影响大于边行,边行干物质、氮磷积累体现边际效应优势;与单作体系相比,间作使玉米大豆植株茎叶营养器官氮转移量均减少,分别降低22.13%、29.85%,转运氮对玉米籽粒氮的贡献率分别下降5.11%、17.45%,且根系吸收氮对籽粒氮的贡献率均高于转运氮对籽粒氮的贡献率。间作能够有效提高系统氮利用效率,较玉米、大豆单作分别提高2.34%、4.62倍,使系统氮效率较单作大豆提高26.82%,较单作玉米降低10.16%,玉米在系统产量中占主导地位,占系统产量的82.27%,土地当量比(LER)达到1.47,系统产量为13110 kg/hm^(2),较单作玉米下降3.96%。【结论】间作优势主要在于促进根系吸收氮向籽粒的分配,提高氮的利用效率。

南充市大豆玉米带状复合种植调研报告

为了解南充市大豆玉米带状复合种植现状,文章以南充市南部县与西充县多个大豆玉米带状复合种植示范区为调研对象,对调研区的基本种植情况、存在问题进行调研,提出促进南充市大豆生产发展建议,包括优选良种,加强田间管理;推进西南丘区小型智能农机装备研发进程;提供政策扶持,加快大豆生物育种步伐,旨在为提升南充大豆单产水平提供参考,助力南充市大豆产业发展。

低磷红壤无机磷组分特征及间作调控作用

为明确间作和施用磷肥对低磷红壤无机磷组分的影响,促进酸性土壤磷肥高效利用,通过田间小区定位试验,采用玉米单作(MM)、玉米//大豆间作(MI)2种种植模式,在4个施磷水平(P2O50、60、90、120 kg·hm^(-2),分别记作P0、P60、P90、P120)下,研究玉米//大豆间作根际土壤无机磷组分变化特征,探讨间作对红壤玉米产量及其可持续性、磷吸收和磷素收支平衡、土壤无机磷组分的调控作用。结果表明,玉米籽粒产量及其可持续性指数(SYI)、磷吸收量随着施磷水平的增加而增加,在P90水平达到最大值。低磷红壤无机磷组分以O-P和Fe-P为主,二者占无机磷库的71.44%~80.18%,施用磷肥显著提高了红壤Fe-P和Al-P的含量与占比。玉米//大豆间作显著提高玉米产量,促进磷的吸收利用,减少土壤磷素盈余量,显著降低红壤O-P、Fe-P、Al-P含量。与单作相比,在P60、P90、P120水平下,间作玉米产量分别显著提高66.70%、52.44%、74.14%,SYI分别显著提高55.31%、42.18%、78.00%,磷吸收量分别显著提高61.97%、48.67%、74.33%,土壤磷盈余量分别显著降低33.39%、27.27%、17.06%。相较于单作,间作红壤中有效磷含量无显著差异,而O-P和Al-P含量在P0、P60、P90、P120水平下分别显著降低20.62%、16.79%、16.62%、18.48%和21.98%、21.08%、20.19%、20.18%,Fe-P含量在P60、P90、P120水平下分别显著降低19.37%、15.78%、17.72%。低磷供应(P0和P60)间作与单作红壤Ca-P含量无显著差异,在P90和P120水平下,间作红壤Ca-P含量降低23.50%和26.70%。随机森林模型分析表明,间作体系下,红壤Fe-P和Al-P是磷吸收的关键无机磷组分,间作总方差解释度较单作提高了7.95%。综上,在低磷红壤上,合理间作通过促进红壤中难溶性无机磷组分的活化增加玉米的磷吸收,具有减少土壤磷素固定、提高玉米产量及其可持续性的潜力。

施氮与种间距离下大豆/玉米带状套作作物生长特性及其对产量形成的影响

为明确施氮和种间距离下套作作物生长特性及其对产量形成的影响。本文以大豆/玉米带状套作系统为研究主体,探究不同氮水平(施氮与不施氮)与种间距离(玉豆间距30、45、60和75 cm、单作100 cm)下作物生长率、干物质积累与分配及产量差异,并对作物干物质积累过程进行拟合,综合分析作物生长规律和产量效益。结果表明:玉米生长率在抽雄期至乳熟期达最大,不施氮下以间距30 cm(MS30)最高,较玉米单作(MM100)高出34.99%。套作大豆生长率在初花期前显著低于单作(SS100),而初花期后高于SS100,以间距60cm(MS60)最高,盛花期—盛荚期在不施氮下较SS100高出78.91%。Logistic方程可较好的拟合玉米、大豆的干物质积累过程,且R2均在0.95以上。与不施氮相比,施氮推迟了玉米干物质积累高峰,提高了干物质积累量;套作大豆生育前期干物质积累慢于单作,而生育后期间距45cm(MS45)、MS60干物质积累逐渐与单作持平甚至超过单作。施氮提高了玉米籽粒干物质分配率而显著提高产量,2年间玉米产量分别提高10.05%、40.90%。随种间距离增加套作大豆产量呈先增后减趋势,以MS60最高,MS30最低,MS60两年间在不施氮与施氮下较MS30分别平均高出23.88%、31.77%。套作下土地当量比均在1.35以上,其中以施氮下MS60最大(1.89)。适宜的种间距离(间距60 cm)可实现套作下玉米和大豆协同生长,提高作物生长率、促进干物质积累与分配、提高系统产量和土地当量比。

植物油包膜控释氮肥在间作玉米-大豆上的施用效果研究

为考察新型植物油包膜控释氮肥对间作玉米-大豆的产量、经济效益、肥料利用率等方面的影响,开展了田间小区试验。试验以不施氮肥(CK)、施用普通尿素(PU)处理为对照;植物油包膜控释氮肥施肥量为全量、减量20%、减量30%等3种,控释氮占总氮量为60%、40%等2种,共设置4个处理。结果表明,在玉米试验中,与PU处理相比,控释氮占总氮量60%的全量、减量20%处理的产量分别显著增产14.70%、7.49%,纯收入分别显著增加3192.80、2680.02元/hm2;控释氮肥处理的氮素利用率为50.14%~53.43%,差异显著。在大豆试验中,与PU处理相比,控释氮占总氮量60%的全量处理显著增产16.67%,纯收入显著增加2725.80元/hm2;控释氮肥处理的氮素利用率为54.12%~57.98%,差异显著。对于玉米-大豆间作栽培,建议全量或减量20%施用控释氮占总氮量60%的植物油包膜控释氮肥。

带状复合种植模式下玉米大豆性状表现与综合效益分析

于2022年引进了5个玉米品种,与鄂豆10号大豆带状复合种植,观察玉米和大豆的相关性状,筛选出适宜的玉米品种,分析综合效益。结果表明:各复合种植模式中,以MY73+鄂豆10号处理的玉米单产、总产、总产值最高,分别为6 655 kg/hm^(2)、8 030 kg/hm^(2)、26 103元/hm^(2);玉米品种MY73在试验中表现为产量最高、株高较矮、综合抗性好,是玉米大豆复合种植模式中较适宜的品种。

玉豆间作对大豆生长发育、产量、品质及群体经济产值的影响

为筛选适宜在本地与玉米间作种植的大豆品种,促进玉豆间作技术的推广应用。本研究以3个福建省春大豆品种(泉豆7号、泉豆13号和泉豆17)及玉米品种金百甜15为材料,以2∶2大豆、玉米行比进行间作种植,以大豆单作和玉米单作为对照,在大豆不同生育时期,测定大豆单作和玉豆间作的大豆株高、叶绿素含量、干物质量,计算叶面积指数和茎占比,分析其变化规律与差异;大豆成熟后,分析大豆单作和玉豆间作的大豆农艺性状、产量及品质差异,计算不同处理下的产量、群体经济产值及土地当量比,分析不同间作组合间的差异,并对大豆农艺性状、产量及群体经济产值进行相关性分析,对玉豆间作模式进行适应性综合评价。结果表明:(1)大豆生育期间:株高在鼓粒期达到峰值,间作种植显著提高大豆株高(P<0.05),且均呈现泉豆7号>泉豆17>泉豆13号的趋势;叶绿素含量和叶面积指数均呈现先增大后减小的趋势,在鼓粒期达到峰值,间作种植显著提高叶绿素含量,降低叶面积指数和大豆各个干物质重,同一生育时期的干物质总量均呈现泉豆13号>泉豆17>泉豆7号的趋势;大豆茎占比呈现先增大后减小的趋势,在开花期达到峰值,且均呈现泉豆7号>泉豆17>泉豆13号的趋势。(2)大豆成熟后:间作种植显著提高大豆株高和底荚高度,其中泉豆7号提高最多,泉豆13号提高最少,泉豆17表现居中;间作种植后,大豆主茎节数显著减少,有效分枝数、单株有效荚数、单株粒数、单株粒重和百粒重均显著降低,其中泉豆13号减少最小,泉豆7号减少最多,泉豆17居中;间作种植显著改变了大豆籽粒蛋白质和脂肪含量,其中蛋白质含量显著降低,脂肪含量显著提高。(3)间作种植均显著降低玉米产量和大豆产量,但均显著提高了群体产量,3个玉豆间作系统的经济总产值从高到低依次为泉豆13号/金百甜15>泉豆17/金百甜15>泉豆7号/金百甜15,分别为30371.15,30125.26和29866.71元·hm^(-2),均显著高于玉米和大豆各自单作模式下的经济产值,对应的间作大豆产量分别为1229.94,1182.37和1137.83 kg·hm^(-2),3个间作系统群体间的经济总产值差异达显著水平,3个间作模式下大豆的产量差异也均达显著水平;3个间作系统的土地当量比均大于1,说明间作种植具有明显优势。(4)相关性分析结果表明,株高和底荚高度与大豆产量、群体总产值均呈显著负相关,大豆产量与群体总产值呈显著正相关。综上,间作种植显著提高大豆株高、底荚高度、叶绿素含量和脂肪含量,显著提高间作群体产量,选择矮秆、茎占比小的大豆品种更容易获得较高的大豆产量及群体经济产值。经比较分析,泉豆13号适宜在泉州与玉米间作种植,并且能获得相对较高的大豆产量及群体经济产值。

基于功能-结构模型的玉米大豆间作不同行向辐射分布研究

【目的】构建不同种植模式和行向的玉米大豆间作功能-结构模型,为解析玉米大豆间作系统的产量优势、生长发育规律及种植模式和行向对光截获、光分配和辐射利用效率的影响提供有力支持。【方法】基于不同种植模式的玉米大豆间作田间试验,解析种植行向如南北行向、东西行向、传统行向(梨树当地长期使用的种植行向,即南偏西40o)对作物生物量、产量和形态结构的影响,构建玉米大豆间作功能-结构模型,模拟不同种植模式和行向下作物群体生长发育和结构变化,量化种植行向对间作系统光截获量和辐射利用效率的影响,并探索玉米大豆间作高光截获量的最佳种植行向。【结果】玉米大豆间作系统的籽粒土地当量比(landequivalentratio,LER)南北行向最高(1.20±0.07),东西行向最低(1.16±0.09)。构建的模型较好地模拟了不同种植方式和种植行向下玉米和大豆的生长发育,与田间实测值相比,玉米株高、单株叶面积和冠层光截获系数的均方根误差(RMSE)分别为0.09—0.14 m、0.04—0.08 m^(2)·plant(-1)和0.07—0.12,大豆株高、单株叶面积和冠层光截获系数的RMSE分别为0.07—0.09 m、0.02—0.04 m^(2)·plant^(-1)和0.09—0.10。传统行向间作系统的累积光截获量最高,为(758.48±1.00)MJ·m^(-2),南北行向和东西行向的辐射利用效率比传统行向分别降低了7.18%、10.57%。【结论】间作种植可以提高玉米生物量和产量,降低大豆生物量和产量。玉米大豆间作种植模式中,种植行向对作物生长有显著影响,矮秆大豆通过改变叶片大小、节间长度和叶柄倾角规避高秆玉米的遮荫影响,以增加受光量和辐射利用效率,最终提高产量。种植行向对群体累积光截获影响较大,间作系统的辐射利用效率与累积光截获量均表现为传统行向>南北行向>东西行向。本研究有助于田间布局优化,为解释不同种植行向玉米大豆间作的光截获和光分配提供了数据支持。

玉米大豆间作对大豆生长发育及质量品质的影响

为研究玉米大豆间作对大豆生长发育及质量品质的影响,以两个福建省春大豆品种泉豆5号(D1)、泉豆12号(D2)和玉米品种金百甜15(Y)为试验材料,在玉米大豆间作和单作(为对照)两种种植模式下分析比较大豆的生长动态、农艺性状、品质产量和经济产值。结果表明:全生育期内,间作模式大豆植株较单作模式总体上表现出株高、叶片叶绿素含量和茎占比增大,叶面积指数和各干物质含量降低的规律;随着生育期的推进,不同种植模式下泉豆5号和泉豆12号的株高、叶绿素含量、叶面积指数、根干重和叶干重均呈现出先增长后减小的趋势,在鼓粒期达到峰值;茎干重、荚果干重和各干物质总量均在成熟期达到最大值;茎占比表现出先增大后减小的趋势,在开花期达到最大值。间作模式大豆株高、底荚高度、主茎节数、蛋白质含量和脂肪含量均高于单作模式,但有效分枝数、单株有效荚数、单株粒数、单株粒重和百粒重均低于单作模式;间作模式显著降低玉米产量和大豆产量,但显著提高了总产量和经济产值。与玉米单作相比,YD1、YD2间作模式中玉米产量分别减产了2.43%、4.19%,玉米大豆总产量分别提高了11.23%、8.14%,经济产值分别增收5206.51元·hm^(−2)(24.28%)、4272.69元·hm^(−2)(19.93%);与大豆单作相比,YD1、YD2间作模式中大豆产量分别减产了38.26%、41.57%,玉米大豆总产量分别提高了402.98%、412.46%,经济产值分别增收17370.07元·hm^(−2)(187.26%)、16860.81元·hm^(−2)(190.49%)。两个间作模式的土地当量比均大于1,说明间作具有明显优势。综上,泉豆5号植株较矮、底荚高度低,单株有效荚数、单株粒数和单株粒重大,茎占比小,间作种植的总产量、经济产值和土地当量比(LER)大,更适合作为泉州地区间作种植的大豆品种。

大豆玉米复合种植模式中2种作物的互作关系

定量化探索中国北方在平水年下,不同大豆玉米复合种植模式的种间竞争与种间互惠关系,以期为旱作条件下选择合理的牧草种植模式提供理论依据。试验选用我国中南部春播区推荐的作物品种大豆铁丰31和玉米强盛199,在旱作区域开展不同大豆玉米带状复合种植模式的大田栽培试验,采用完全随机区组设计4种大豆玉米带状复合种植模式,同时以大豆与玉米清种作为对照,测定不同种植模式下的生物量、邻体效应指数(RII),比较不同种植模式下大豆和玉米的互作关系。结果显示,大豆RII为-0.28~0.13,玉米RII为-0.28~0.12。在6行大豆3行玉米(S6M3)复合种植模式下,大豆和玉米的生物量较清种对照分别增加了28.95%和27.79%,且高于其他复合种植模式下作物生物量;大豆和玉米的RII分别为0.13和0.12,二者存在正相互作用。综上,在与试验区年降雨量相差不明显的旱作区域,选择S6M3复合种植模式有望提高青贮饲料产量。

玉米与大豆间作对干物质累积分配、产量相对竞争 及土地当量比的影响

为充分利用光热水肥土资源,间作是提高单位土地面积生产力、作物产量和经济效益的一种重要种植方式。设置了玉米与大豆间作行比M4S6(4∶6)、M2S4(2∶4)、M4S4(4∶4),玉米单作(MCK)与大豆单作(SCK)5种种植模式,研究了玉米与大豆间作对干物质累积分配、产量相对竞争及土地当量比的影响。结果表明:不同生育时期间作处理玉米干物质累积均大于单作玉米,M4S6、M2S4大豆干物质累积高于单作大豆。间作处理营养干物质输出量均大于单作,玉米与大豆间作处理显著增加了营养干物质的输出量,呈现处理M2S4>M4S6>M4S4>CK,玉米与大豆间作其输出率低于贡献率,间作玉米的输出率低于大豆,而贡献率显著高于大豆。玉米间作处理雌穗分配比重显著大于单作处理,处理M4S6显著提高雌穗干物质分配比重,结荚期间作处理大豆干物质向豆荚分配比重低于单作处理,成熟期豆荚干物质分配比重显著升高,处理M4S6豆荚干物质分配比重最大。处理M2S4、M4S6、M4S4玉米产量分别为单作玉米MCK的70.81%、84.58%、66.33%,大豆产量分别为单作大豆SCK的9.89%、17.97%、14.18%,处理M4S4产量相对竞争优势极强,处理M4S6、M2S4比M4S4竞争优势显著减弱,处理M4S6、M2S4、M4S4的产量土地当量比LER均大于1,处理M4S6产量土地当量比最大,其次是M2S4,处理M4S6、M2S4比M4S4产量土地当量比分别增加了19.42%、12.62%。处理M4S6、M2S4经济效益比单作玉米MCK分别增加了19.41%、15.75%,比单作大豆分别增加了113.01%、106.47%。整体上,相较其它间作处理,M4S6是最有益于挖掘玉米与大豆间作优势,提高土地生产力的间作模式。