有机高粱与不同作物间作对群体产量及效益的影响

为了明确有机高粱与不同作物间作对群体产量及效应的影响,以有机高粱指定品种“红缨子”和本地花生、大豆、向日葵、白云豆、眉毛豆、四季豆、米豆、绿豆、红苕为试验材料,比较分析了有机高粱和不同作物间作对群体产量和效益的影响。结果表明,无藤豆类作物四季豆、眉毛豆、白芸豆可作为有机高粱间作的首选作物。     

Intercropping Studies in Peanut (Arachis hypogaea L.)

With a view to study the effect of intercropping and plant geometries in peanut cv. VRI-1 , a held experiment was conducted at Area Agronomic Centre, Tamil Nadu Co-operative Oilseeds Growers' Federation Limited, Neyveli, India during winter season 1989, (November 89–April 90) under irrigated condition. Three intercrops viz., pigeonpea, sunflower and finger millet were tested at two plant geometries viz., paired rows of 40/20 cm and 45/15 cm. The study indicated that pigeonpea was compatible with peanut and their combination resulted in higher peanut kernel equivalent yield and higher profit. Sunflower and finger millet depressed the base crop yield and found to be unsuitable for intercropping in peanut. Base crop yield was not influenced by the plant geometries.     

Grain Yield of Intercropped Sorghum and Pearl Millet as Influenced by Sorghum Genotype and Cropping Pattern

Intercropping of sorghum and pearl millet with different growth cycles is used widely in third-world countries to ensure and increase yields. However, it is questionable whether yield increases because of intercropping can be maintained under more developed systems, since temporal differences are necessary to allow mechanized planting and harvesting.
Three sorghum hybrids with expected growth cycles from 90 to 110 days were planted in sole stands and in alternate rows and mixed within the rows with a pearl millet hybrid having a growth cycle similar to that of the early sorghum. Sole stands of millet also were included. The plots were planted at three locations in Kansas, two dryland and one including dryland and irrigated. Results show that yields were consistently highest in sole stands of sorghum, owing to the higher yield level of sorghum. No yield increase could be found on a land equivalent ratio basis, indicating no intercropping advantages. However, under good moisture conditions, a tendency toward yield increase was observed with the later maturing sorghums, which had 1–2 weeks of grain filling after the millet was mature. When moisture supply was insufficient, millet showed higher competitiveness for water than sorghum, and sorghum was adversely affected more than pearl millet was favored. It was concluded that moisture conditions have to be good and that temporal differences between sorghum and millet have to be greater than those used in this experiment to achieve intercropping yield advantages.     

Crop Rotation to Improve Agricultural Production in Sub-Saharan Africa

A three years' trial was conducted in a farmers' field in northern Ghana to evaluate the effect of sole crops (cotton, cowpea, groundnut, soybean, and sunflower) planted once or twice on yield of the staple foods of the region, maize and sorghum. Sole cropping for only one year already resulted in significant yield increases for maize and partly for sorghum compared to the conventional cropping of mixed stands of maize–sorghum or maize–groundnut and natural fallow. Lowest yield of maize and sorghum was obtained where these cereals followed maize–sorghum (monoculture). Intercropping of maize with groundnut led to subsequent maize and sorghum yields which were similar to those obtained after maize–sorghum. After growing legumes and sunflower for one year the grain and straw yield of maize and sorghum was significantly higher in the two consecutive years than after cereal (maize–sorghum) monoculture. In this trial maize and sorghum were found to be not as tolerant to the disadvantages of monoculture or preceding cereals–legumes mixture. The results suggest that continuous intercropping with cereals under the given conditions has negative effects on soil fertility and can lead to an increase in soil-borne pests and troublesome weeds like Striga comparable to monocropped cereals.     

Growth and Yields of Intercropped Sorghum and Sunflower (Helianthus annuus L.) in Semi-arid Nigeria

Effect of five planting patterns on the growth, yield and yield components of intercropped sunflower and sorghum was studied during 1989–90 planting seasons at University of Maiduguri, Nigeria. Generally, intercropping depressed the performance of sorghum more than sunflower. Sorghum plants grown in alternate hills with sunflower had the shortest stems, the least dry matter and total seed yields per hectare, while the highest dry matter and seed yields were obtained from sorghum planted in five alternating rows with sunflower. Similarly, in sunflower, plants grown in five alternating rows with sorghum had the highest yields compared with other planting patterns, but there were no significant differences in the dry matter and total seed yields of sorghum and sunflower intercropped in three and five alternating rows. Light transmission, leaf area index and yields of both crops followed similar trends under the various planting patterns. Interplanting in five alternating rows that allowed the highest leaf area also allowed the lowest light transmission and produced the highest yields. Land use efficiency was highly improved under three and five rows interplanting by 52 and 74 % respectively.     

Effects of Population on Physiological Growth Parameters of Pigeonpea Genotypes in Sole and Intercropped Stand with Sorghum CO 22

A field experiment was conducted during khariff 1984 in sandy clay loam soil under irrigated condition at the Tamil Nadu Agricultural University, Coimbatore, with a view (i) to find out the possibility of introducing short duration dwarf variety of sorghum CO 22 as an intercrop with pigeonpea genotypes, (ii) to study the effect of different plant population levels and intercropping of sorghum CO 22 on pigeonpea genotypes, and (iii) to find out compatible pigeonpea genotypes and plant population level for pigeonpea based intercropping system with sorghum CO 22.
It was observed that increased plant density significantly increased the dry matter production, leaf area index (LAI) and crop growth rate (CGR) during early stages and reduced the net assimilation rate (NAR), relative growth rate (RGR) and CCR during later part of the growth. Intercropping of sorghum CO 22 significantly reduced the dry matter production LAI, CGR, NAR and RGR. Plants in the intercropped stands recorded higher CGR, NAR and RGR during later part of the growth. Among pigeonpea genotypes CO 5 was much affected due to intercropping with sorghum CO 22.     

间作和双接种对玉米和菜豆生长的影响

为了验证菜豆玉米间作的可行性及双接种丛枝菌根真菌和根瘤菌在此间作体系中的影响。通过采用盆栽试验的方式,测定了不同栽培及接种方式下玉米和菜豆的一些生理指标如：生物量、氮磷钾元素的含量及吸收量、叶绿素SPAD值、菌根侵染率等。结果表明：单接种时,单作下的玉米和菜豆的总生物量分别是间作下的3.26 倍和1.25 倍;双接种时也分别达到了3.08 倍和1.25 倍。然而单接种时玉米和菜豆间作后每盆的吸氮量和吸磷量分别是间作下的1.11 倍和1.05 倍;双接种时则均为1.16 倍。接种丛枝菌根真菌后玉米及菜豆的生物量、氮磷钾元素的含量及吸收量、叶绿素含量等差异均不显著,而菜豆的根瘤数却降低了。试验研究表明：间作抑制了菜豆及玉米的生长,但促进了二者对氮磷元素的吸收利用;接种丛枝菌根真菌对玉米及菜的生长无促进作用,对二者吸收利用氮磷钾元素也无明显促进,而且还抑制了根瘤菌侵染菜豆。     

Agronomic Performance of Sorghum and Groundnut Cultivars in Sole and Intercrop Cultivation under Semiarid Conditions

The performance of sorghum and groundnut cultivars was studied in sole cropping and intercropping systems at Babile in the semiarid area of eastern Ethiopia in 1996, 1997 and 1999. On average, late-maturing cultivars of groundnut and sorghum gave higher dry pod yield and grain yield, respectively, when intercropped with early-maturing cultivars of the associated crops. The significant variation among groundnut cultivars in yield and yield components under intercropping with sorghum cultivars revealed that sole cropping may not provide the appropriate environment for selecting varieties intended for use in intercropping. The productivity of intercropped groundnut and sorghum cultivars, as determined by total land equivalent ratios (LER), was higher than sole cropping, indicating the presence of temporal complementarity in the use of growth resources. A mean yield advantage of 32 % was obtained under intercropping.     

灌溉制度对甜瓜/向日葵间作系统叶片水分状况和水分利用效率的影响

为优化甜瓜/向日葵间作模式节水灌溉关键技术,提高绿洲灌区灌溉水分利用效率.试验以甜瓜和向日葵为试材,研究9种灌溉制度下甜瓜/向日葵间作系统和2种作物单作的叶片水分状况和水分利用效率.结果 表明,甜瓜/向日葵间作系统的水分效率显著高于甜瓜单作和向日葵单作,分别提高30.3％和107.8％,间作显著提高了甜瓜成熟期叶片的水...     

糜子绿豆带状种植下糜子的氮素积累、代谢及产量变化

禾豆间作是一种高效的生态种植模式,为明确糜子-绿豆合理间套作种植模式下糜子对养分高效利用的机制,于2017—2018年在榆林小杂粮综合试验示范站,以单作糜子(SP)为对照,设糜子(P)-绿豆(M)4种间作模式[2∶2(2P2M)、4∶2 (4P2M)、4∶4 (4P4M)、2∶4 (2P4M)],分析糜子开花期和成熟期不同器官干物质积累、氮素含量及植株氮积累量,以期探讨叶片和根系氮素代谢的变化规律,进一步挖掘不同间作模式对糜子产量及其构成因素的调控效应。结果表明,糜子-绿豆间作可显著增加糜子开花期根系、茎秆、叶片和鞘的氮素含量,使成熟期穗的氮含量比单作增加10.9%～15.9%;间作有利于促进糜子器官的生长发育,与单作相比,间作模式下糜子成熟期干物质积累量两年试验平均提高11.6%～32.1%,植株氮素积累量增加12.8%～36.9%,其中糜子叶片和茎秆的氮素转运量分别比单作增加51.7%～78.9%和24.1%～55.6%,叶片对于穗的氮素贡献率增加40.6%～66.9%。糜子-绿豆间作模式可显著调节糜子旗叶和根系的氮素代谢,硝酸还原酶活性、谷氨酰胺合酶活性、可溶性蛋白含量及游离氨基酸含量均有不同程度的增加,2P4M处理下达到最大值。植株生理代谢、氮素营养的合理调控显著改善了糜子产量及其构成因素,产量表现为2P4M4P4M2P2M4P2MSP。综上所述,糜子-绿豆间作模式可促进糜子生育后期的氮素积累、转运及氮素代谢,延缓了植株的衰老,提高糜子产量,表现出明显的间作优势。本试验条件下,2P4M是陕北地区糜子-绿豆最佳的间作配比。     

Effect of Drought Stress on Yield and Quality of Maize/Sunflower and Maize/Sorghum Intercrops for Biogas Production

Intercropping represents an alternative to maize (Zea mays L.) monoculture to provide substrate for agricultural biogas production. Maize was intercropped with either sunflower (Helianthus annuus L.) or forage sorghum [Sorghum bicolor (L.) Moench] to determine the effect of seasonal water supply on yield and quality of the above‐ground biomass as a fermentation substrate. The two intercrop partners were grown in alternating double rows at plant available soil water levels of 60–80 %, 40–50 % and 15–30 % under a foil tunnel during the years 2006 and 2007 at Braunschweig, Germany. Although the intercrop dry matter yields in each year increased with increasing soil moisture, the partner crops responded quite differently. While maize produced significantly greater biomass under high rather than low water supply in each year, forage sorghum exhibited a significant yield response only in 2006, and sunflower in none of the 2 years. Despite greatly different soil moisture contents, the contribution of sorghum to the intercrop dry matter yield was similar, averaging 43 % in 2006 and 40 % in 2007. Under conditions of moderate and no drought stress, sunflower had a dry matter yield proportion of roughly one‐third in both years. In the severe drought treatment, however, sunflower contributed 37 % in 2006 and 54 % in 2007 to the total intercrop dry matter yield. The comparatively good performance of sunflower under conditions of low water supply is attributable to a fast early growth, which allows this crop to exploit the residual winter soil moisture. While the calculated methane‐producing potential of the maize/sorghum intercrop was not affected by the level of water supply, the maize/sunflower intercrop in 2006 had a higher theoretically attainable specific methane yield under low and medium than under high water supply. Nevertheless, the effect of water regime on substrate composition within the intercrops was small in comparison with the large differences between the intercrops.     

Comparative assessment of maize,finger millet and sorghum for household food security in the face of increasing climatic risk

Questions as to which crop to grow, where, when and with what management, will be increasingly challenging for farmers in the face of a changing climate. The objective of this study was to evaluate emergence, yield and financial benefits of maize, finger millet and sorghum, planted at different dates and managed with variable soil nutrient inputs in order to develop adaptation options for stabilizing food production and income for smallholder households in the face of climate change and variability. Field experiments with maize, finger millet and sorghum were conducted in farmers’ fields in Makoni and Hwedza districts in eastern Zimbabwe for three seasons: 2009/10, 2010/11 and 2011/12. Three fertilization rates: high (90 kg N ha⁻¹, 26 kg P ha⁻¹, 7 t ha⁻¹ manure), low (35 kg N ha⁻¹, 14 kg P ha⁻¹, 3 t ha⁻¹ manure) and a control (zero fertilization); and three planting dates: early, normal and late, were compared. Crop emergence for the unfertilized finger millet and sorghum was <15% compared with >70% for the fertilized treatments. In contrast, the emergence for maize (a medium-maturity hybrid cultivar, SC635), was >80% regardless of the amount of fertilizer applied. Maize yield was greater than that of finger millet and sorghum, also in the season (2010/11) which had poor rainfall distribution. Maize yielded 5.4 t ha⁻¹ compared with 3.1 t ha⁻¹ for finger millet and 3.3 t ha⁻¹ for sorghum for the early plantings in the 2009/10 rainfall season in Makoni, a site with relatively fertile soils. In the poorer 2010/11 season, early planted maize yielded 2.4 t ha⁻¹, against 1.6 t ha⁻¹ for finger millet and 0.4 t ha⁻¹ for sorghum in Makoni. Similar yield trends were observed on the nutrient-depleted soils in Hwedza, although yields were less than those observed in Makoni. All crops yielded significantly more with increasing rates of fertilization when planting was done early or in what farmers considered the ‘normal window’. Crops planted early or during the normal planting window gave comparable yields that were greater than yields of late-planted crops. Water productivity for each crop planted early or during the normal window increased with increase in the amount of fertilizer applied, but differed between crop type. Maize had the highest water productivity (8.0 kg dry matter mm⁻¹ ha⁻¹) followed by sorghum (4.9 kg mm⁻¹ ha⁻¹) and then finger millet (4.6 kg mm⁻¹ ha⁻¹) when a high fertilizer rate was applied to the early-planted crop. Marginal rates of return for maize production were greater for the high fertilization rate (>50%) than for the low rate (<50%). However, the financial returns for finger millet were more attractive for the low fertilization rate (>100%) than for the high rate (<100%). Although maize yield was greater compared with finger millet, the latter had a higher content of calcium and can be stored for up to five years. The superiority of maize, in terms of yields, over finger millet and sorghum, suggests that the recommendation to substitute maize with small grains may not be a robust option for adaptation to increased temperatures and more frequent droughts likely to be experienced in Zimbabwe and other parts of southern Africa.     

Field evaluation of mixed-seedlings with rice to alleviate flood stress for semi-arid cereals

Flash floods, erratically striking semi-arid regions, often cause field flooding and soil anoxia, resulting in crop losses on food staples, typically pearl millet (Pennisetum glaucum L.) and sorghum (Sorghum bicolor (L.) Moench). Recent glasshouse studies have indicated that rice (Oryza spp.) can enhance flood stress tolerance of co-growing dryland cereals by modifying their rhizosphere microenvironments via the oxygen released from its roots into the aqueous rhizosphere. We tested whether this phenomenon would be expressed under field flood conditions. The effects of mix-planting of pearl millet and sorghum with rice on their survival, growth and grain yields were evaluated under controlled field flooding in semi-arid Namibia during 2014/2015–2015/2016. Single-stand and mixed plant treatments were subjected to 11–22 day flood stress at the vegetative growth stage. Mixed planting increased plant survival rates in both pearl millet and sorghum. Grain yields of pearl millet and sorghum were reduced by flooding, in both the single-stand and mixed plant treatments, relative to the non-flooded upland yields, but the reduction was lower in the mixed plant treatments. In contrast, flooding increased rice yields. Both pearl millet–rice and sorghum–rice mixtures demonstrated higher land equivalent ratios, indicating a mixed planting advantage under flood conditions. These results indicate that mix-planting pearl millet and sorghum with rice could alleviate flood stress on dryland cereals. The results also suggest that with this cropping technique, rice could compensate for the dryland cereal yield losses due to field flooding.     

Shade Effects on Phaseolus vulgaris L. Intercropped with Zea mays L. under Well-Watered Conditions

Field experiments were carried out under unstressed conditions of soil water during two summer crop growing seasons (1998–99 and 1999–2000 seasons) in a South African semi‐arid region (Bloemfontein, Free State, South Africa). The aim of this study was to investigate shade effects on beans intercropped with maize in terms of plant mass and radiation use. The experimental treatments were two cropping systems (no shading/sole cropping and shading/intercropping) and two row orientations (north–south and east–west). At the top of bean canopies shaded by maize, incident radiation was reduced by up to 90 %. Shading reduced total dry matter of beans by 67 % at the end of the growing season, resulting in yield losses. The dry matter partitioning into leaf and stem (the ratios of leaf and stem to total biomass) was about 50 % higher in intercropping than sole cropping. In contrast, intercropped beans had 40 % lower dry matter partitioning into pod (the ratio of pod to total biomass). Fraction of radiation intercepted by sole‐cropped beans steeply increased until canopy closure (0.9) and then slowly decreased, while fraction of radiation intercepted by intercropped beans remained constant between 0.0 and 0.2 throughout the growing seasons. However, intercropped beans had 77 % higher radiation use efficiency (RUE) than sole‐cropped beans. In contrast, for maize, no effect of intercropping (shading) was found on growth, partitioning, yield, radiation interception or RUE. Consequently, lower bean yield losses can be attained in association with late shading rather than early shading. This can be controlled by growing crops with different temporal and spatial treatments. As regards row treatment, no effect of row direction was found on growth, partitioning, yield, radiation interception or RUE.     

Accelerating gene discovery in climate-resilient and nutrient-rich major and minor millets through genome-wide association studies: Progress and prospects

Millets are known for their resilience and nutritional benefits and hence believed to have a promising role in ensuring food and nutritional security under changing climatic conditions. Research on millets has intensified in recent years, especially in dissecting the genetic components of yield, stress tolerance and nutritional quality traits. Recent advances in next-generation sequencing, bioinformatics and associated statistical procedures for genome-wide association studies (GWAS) have provided wide opportunities to resolve the genetic complexity of polygenic traits by measuring historical and evolutionary recombination events in the natural population(s). During the past decade, GWAS has been successfully employed to identify key genes controlling growth, development, stress tolerance, nutrient use efficiency and nutritional quality traits in sorghum, pearl millet, foxtail millet and finger millet. However, progress in other minor millets is still in its infancy. Genetic dissection of these complex traits in millets may pave the way for genetic alteration of climate resilience, photosynthesis and nutrient accumulation in rice and wheat. In this review, progress in GWAS analysis in detecting QTLs underlying complex traits in sorghum and other millets is highlighted.     

Effect of Population Levels of Soybean on Physiological Growth Parameters of Sorghum CO 24 in Sole and Intercropped Stand

A field experiment was conducted during kharif, 1985 and summer, 1986 in sandy clay loam soil under irrigated condition at Tamil Nadu Agricultural University, Coimbature, with a view (i) to assess the suitable method of planting of sorghum CO 24 when intercropped with soybean, (ii) to evaluate the suitable planting ratio of sorghum - soybean intercropping system, (iii) to find out the compatible population level of soybean when intercropped with sorghum CO 24.
Direct sown sorghum at 4: 2 and 2: 2 recorded grater leaf area (LA) compared to transplanted sorghum in both kharif and summer. Sorghum transplanted with 14 days old seedlings recorded higher Crop Growth Rate (CGR) compared to 21 days old seedlings. Increased Net Assimilation Rate (NAR) were recorded in sorghum transplanted with 14 days old seedlings as compared to direct sown and 21 days old transplanted crop. Transplanted sorghum recorded higher Relative Growth Rate (RGR) as compared to direct sown sorghum. Summer sorghum recorded higher Relative Growth Rate (RGR) as compared to kharif season.     

Respiration and Growth of Sorghum and Sunflower under Predicted Increased Night Temperatures1

Little information exists concerning how crops will respond to the predicted increased night temperatures. The objective of this work was to determine if respiration and growth of sorghum [Sorghum bicolor (L.) Moench], a C, plant, and sunflower (Helianthus annuus L.), a C₃ plant, are affected when the night temperature is increased by 5°C compared to the long-term (19 year) average night temperature in June in Kansas. Sorghum and sunflower were grown in two walk-in growth chambers with either the ambient night temperature (21C) or a high night temperature (26C). Day temperature was the same for all plants (27C). Both sunflower and sorghum had higher respiration rates under the elevated night temperature than under the ambient temperature. The average respiration rate of sunflower grown under elevated night temperature increased by 19% (0.89 vs. 0.75 μmol m^?2 s^?1) and that of sorghum by 44 % (0.52 vs. 0.36μmol m^?2s^?1). After 74 days, sunflower plants grown under the ambient night temperature were 30.2 cm taller than sunflower plants grown under the elevated night temperature; sorghum plants under the ambient temperature were 24.8 cm taller. Sunflower plants grown under the elevated night temperature formed flowers one week earlier than those grown under the ambient temperature. Sorghum formed no flowers by 74 days. Results suggest that, if climate change does increase night temperature, respiration will be increased more in C₄, than C₃ plants.     

多样性种植模式对糯高粱生长及高梁炭疽病发生的影响

旨在阐述多样性种植模式对于糯高粱农艺性状、生理特性的影响及防控高梁炭疽病的效果,为推广糯高粱栽培技术和防控高梁炭疽病进一步提供理论依据。采用糯高粱与大豆、花生间套作,同时应用隔年换带轮作技术,结果表明：与单作糯高梁比,多样性种植模式对糯高梁的穗长、千粒重、穗粒重等农艺性状有一定影响;多样性种植模式对糯高粱开花期的净光合速率、蒸腾速率、气孔导度、胞间CO2浓度等光合特性有显著性影响;多样性种植模式对高梁炭疽病发病株率、病情严重度分级、病情指数有显著性影响;对高粱炭疽病的防控,A2B2种植模式相对防控效果最好,高达71.95%。糯高梁与大豆、花生间套作的多样性种植模式对糯高粱生长有影响,能够提高糯高粱光合能力,有效控制高梁炭疽病的发生,对大面积生产具有较大的利用价值。     

Evaluation of Intercropping Cassava/Corn/Beans (Phaseolus vulgaris L.) in Northeast Brazil

Cassava, corn and drybeans were tested under sole cropping and under all possible intercropping combinations in Paraiba State, Northeast Brazil. The crops were planted with and without fertilizer (N, P, K), which generated fourteen cropping systems. Yields of beans were not affected by either intercropping systems or fertilization. Yields of corn and cassava were affected by intercropping systems, fertilizer, and cropping systems fertilizer interaction. LER values were significantly different among cropping systems but were not affected by fertilization. This indicates that the advantage of intercropping was not improved by the addition of nutrients.     

Intercropping Maize with Climbing Beans, Cowpeas and Velvet Beans

When one of the crops is a legume, intercropping has potential to reduce fertilizer nitrogen (N) needs and increase food quality. Total dry matter (DM) and grain yields of different plant populations of intercropped maize ( Zea mays L.) and climbing beans ( Phaseolus vulgaris L.), cowpeas ( Vigna unguiculata [L.] Walp.), or velvet beans ( Mucuna pruriens [L.] DC. var utilis [Wight] Bruck.) were compared in two experiments. Maize populations were 40,400 and 50,500 plants ha⁻¹ in combination with climbing bean populations of 0, 20,200, 40,400 and 80,800 plants ha⁻¹ in Experiment 1. In the second experiment, climbing beans, cowpeas and velvet beans at 215,200 plants ha⁻¹ were intercropped with maize at 64,600 plants ha⁻¹. Climbing beans contributed up to 5% to total DM yields in the first experiment. In the second experiment legume contributions to total DM were 20% for climbing beans, 12% for cowpeas and 8% for velvet beans. Increasing populations of maize and climbing beans increased grain and DM yields. Dry matter yield of maize was lowered by intercropping. However, DM yields of the intercrop were not different to maize sole cropped. Maize/cowpeas produced more total DM than maize/climbing beans. Cowpeas increased the total yield of crude protein by over 15% without lowering total DM yield of the intercrop compared to maize alone and are promising as a legume for intercropping with maize. Climbing beans show little promise as a possible legume for intercropping with maize.