Impacts of climate change on the yields of leguminous crops in the Guinea Savanna agroecological zone of Ghana

The impacts of climate change on crop yields are receiving renewed interest,with focus on cereals and staple crops at the regional and national scales.Yet,the impacts of climate change on the yields of leguminous crops in the local context has not been explored.Thus,an in-depth understanding of climate change in the local context may support the design of locally relevant adaptation responses to current and future climate risks.This study examined the impacts of climate variables(annual rainfall,annual average temperature,rainfall indices(rainfall onset,rainfall cessation,and the length of rainy days),and the number of dry days)on the yields of leguminous crops(groundnuts,cowpeas,and soybeans)in the Guinea Savanna agroecological zone of Ghana during the period of 1989-2020.The data were analysed using Mann-Kendall’s trend,Sen’s slope test,correlation analysis,and Multiple Regression Analysis(MRA).The findings revealed that annual rainfall,annual average temperature,rainfall onset,rainfall cessation,and the length of rainy days,and the number of dry days all showed varied impacts on the yields of groundnuts,cowpeas,and soybeans.The trend analysis detected a marginal decrease in the amount of rainfall,rainfall onset,and the number of dry days from 1989 to 2020(P>0.050).Annual average temperature and the length of rainy days substantially varied(P<0.050)from 1989 to 2020,showing an increasing trend.The findings also showed a marked upward trend for the yields of groundnuts,cowpeas,and soybeans during 2005-2020.The climate variables analysed above increased the yields of groundnuts,cowpeas,and soybeans by 49.0%,55.0%,and 69.0%,respectively.The yields of groundnuts,cowpeas,and soybeans fluctuated with the variability of 30.0%,28.0%,and 27.0%from 2005 to 2020,respectively.The three leguminous crops under study demonstrated unpredictable yields due to the variations of annual rainfall,annual average temperature,rainfall onset,rainfall cessation,the length of rainy days,and the number of dry days,which stressed the need for agricultural diversification,changing planting dates,using improved seed variety,and irrigation to respond to climate change.The results of this study implied that climate change considerably impacts crop production in the Guinea Savanna agroecological zone of Ghana,emphasizing the urgency of locally based and farmer-induced adaptation measures for food security and resilient agricultural systems.

Comparison on the Tolerance of Cruciferous Crops and Leguminous Crops to Microcystin

[Objective] To study the differences in the tolerance of leguminous crops and cruciferous crops to microcystin （MC）. [Methed] The cruciferous typical crops oilseed rapes, pakchois, cabbages and leguminous typical crops soybeans, peas and broad beans were selected as the materials to test the effects of MC of differ- ent concentrations on the germination, growth and development of leguminous crops and cruciferous crops. The measurement indicators included germination rate, plant height, chlorophyll, etc. [Result] The MC had great effects on the oilseed rape and pakchois of cruciferous crops, and smaller effects on cabbage, while the leguminous crops were generally not affected. [Conclusion] Leguminous crops are more tolerant to MC than cruciferous crops and more preferential in MC polluted regions.

Rumen methane output and fermentation characteristics of gramineous forage and leguminous forage at differing harvest dates determined using an in vitro gas production technique

An in vitro rumen gas production technique was employed to determine the methane production and fermentation characteristics of Leymus chinensis and Medicago ruthenica at differing harvest dates（May 15,May 30,June 30,July 30,August 30 and September 30）,which are sequential phases within a single continuous growth of two 10-year-old pastures.To quantify the rate of degradation and compare in vitro rumen fermentation characteristic,a logistic-exponential model,where initial gas volume was zero（LE_0）,was used to fit gas production and methane output results.Dried,milled forage samples were incubated in vitro for 72 h at 39℃ and gas production was recorded intermittently throughout the incubation and gas samples were collected to measure methane production.Results showed that there were significant interactions between species and harvest for all chemical composition variables（P〈0.001） and condensed tannin content（P〈0.001）.L.chinensis produced more total gas and methane than M.ruthenica（P〈0.001）.Both total gas and methane production decreased lineally（P〈0.001） with advancing harvest date.The degradation rates of L.chinensis and M.ruthenica harvested on September 30 were lower than those on the other harvest dates（P〈0.01）.M.ruthenica fermented fluid had higher concentration of ammonia N（P〈0.05） and molar proportions of isobutyrate（P〈0.01）,valerate（P〈0.001） and isovalerate（P〈0.01） in total volatile fatty acids than L chinensis.Furthermore,concentration of isovalerate decreased cubically with advancing harvest date（P〈0.05）.In conclusion,M.ruthenica produced less methane than L.chinensis and the total gas and methane production decreased with advancing harvest date for both species,which may be due to the changes in contents of chemical compositions and condensed tannin in forages.

Short Term Leguminous Trees-Tillage Interactions and Their Effect on Soil-Water Content in a Semi-Arid Agroforestry Parkland

Agricultural activities that encourage slashing, burning and ploughing greatly affect the soil structure and soil organic matter on which soil water retention depends. In this study, we hypothesized that inclusion of rotational leguminous tree species improves soil water retention in a semi-arid conservation agriculture system. In a study done in Kibwezi, semi-arid eastern Kenya, results showed that the amount of water retained in the different soil strata from plots with different tree species and tillage practices was highly significant (P = 0.032). Plots with planting basins and Gliricidia sepium and Faidherbia albida tree species retained more water in both the upper and lower strata. Plots with G. sepium tree species under planting basins and zero tillage under F. albida had significantly higher soil organic carbon levels than plots that were managed under ridges and ploughing (P = 0.002). On the other hand, bulk density in plots with planting basins and zero tillage and ridges ranged between 1.35 g/cm3 and 1.53 g/cm3. Conventional tillage plots had bulk density values of 1.65 g/cm3 and 1.72 g/cm3 in the upper and lower strata respectively. The time-dependent nature of rotational leguminous tree species on soil organic matter and soil water retention in the semi-arid conservation agriculture system highlights the importance of considering these species for improving organic carbon and water retention for improved crop production.

豌豆豆球蛋白(leguminA)基因的PCR扩增与鉴定

豆类的贮存蛋白是人类的植物蛋白主要来源之一,稻米平均蛋白质含量只有8％,而且人类必需的赖氨酸含量较少。如果将较富赖氨酸的豆类贮存蛋白基因转移到水稻中,提高稻米的蛋白质和赖氨酸等氨基酸的含量,是改善米质的重要途径之一。 Sun首先从法国菜豆中分离出菜豆贮存蛋白基因(Gl),随后。

Functional relationships of nodulation response and biomass production at nursery stages of two fast-growing, leguminous-multipurpose tree species in Bangladesh: Albizia saman and Leucaena leucocephala

This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass) in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant differences over time(p < 0.05) in all variables except in the root-shoot ratio(oven-dry) of L. leucocephala. The study also showed significant differences(p < 0.05) in nodule formation and biomass production at the end of the study period between the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong positive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass(root biomass and shoot biomass) in both species. The results obtained using principal component analysis(PCA) and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass(shoot green weight and shoot oven-dry weight) is positively correlated with PC1(with an eigenvalue of 7.50) and root length is positively correlated with PC2(with an eigenvalue of 0.19) in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass(root green weight and root oven-dry weight), shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2(with an eigenvalue PC1 of 6.92 and PC2 of 0.49).

Protein Bodies in Cotyledon Cells Exhibit Differential Patterns of Legumin-Like Proteins Mobilization during Seedling Germinating States

Olive (Olea europaea L.) tree is one of the most extensive and important agricultural crop in Mediterranean countries due to its beneficial health and nutritional properties and its high economic value. Currently, olive tree constitutes the sixth most important cultivated plant in the world, spreading from the Mediterranean region of origin to new production areas such as Australia, South and North America and South Africa. However, the mobilization processes of storage materials i.e. reserve proteins during seed germination, which are largely involved in essential physiological process including plant growth and development, remain poorly understood. Morphometric and immunohistochemistry analyses of protein bodies contained in olive seed storage tissues, cotyledon and endosperm, were performed by using different microscopy techniques, including light (bright-field and fluorescence) microscopy and transmission electron microscopy. Furthermore, we used legumin-like proteins (11S-type globulins) as a molecular marker to study the mobilization of reserve proteins from PBs of cotyledons at germinating seedling stages by using immunofluorescence assays. Results demonstrated that cotyledon and endosperm are characterized by distinct PBs populations containing legumin-like proteins, distinctly discriminated by the number of PBs per cell and tissue, size, immunofluorescence and histochemical staining. These features reflect differential PBs biogenesis during development and maturation processes in olive seed tissues endosperm and cotyledon, in relation to proteins (polypeptides) final composition, SSPs processing and/or packaging during seed maturation. Three different mobilization patterns of legumin-like proteins were identified for the first time in cotyledon PBs during seedling germinating process. Mature proteins composition and/or processing, cell types and enzyme composition and/or differential activation have been discussed as key features determining how proteins mobilize from PBs for further degradation in the cotyledon.

Salt Stress Effects on Germination, Plant Growth and Accumulation of Metabolites in Five Leguminous Plants

The investigation was conducted to determine physiological criteria of early selection for salt tolerant leguminous plants. Plants were subjected to 5 levels of salt stress at the roots （0, 50, 100,150 and 200 mM NaCI）. Results showed that sodium chloride had an underrating effect on growth of stems and seed germination of the species studied. The germination rates of seeds of Glycine max and Phaseolus vulgaris （sensitive glyeophytes） were affected from 3 g/L of NaCl, with critical thresholds at 9 and 12 g/L respectively. In contrast, critical thresholds with Mucunapoggei （facultative halophyte）, Vigna unguiculata （moderately tolerant glycophyte） and P. adenanthus （natural halophyte） was found to be above 21 g/L. The reduction of stems growth rate were not significant in P. adenanthus whereas in M. poggei and V. unguiculata this inhibition was observed just when nutritive solutions were enriched with 200 mM. The lipid contents were reduced in all the species under salt stress, whereas proteins and proline contents in the leaves were substantially increased in tolerant species （M. poggei, P. adenanthus and V. unguiculata）. In contrast, proteins and leaf proline contents were negatively affected by salt concentration to G. max and P. vulgaris. Seed germination, proteins and proline could be used as physiological criteria of early selection for salt tolerant leguminous plants.

Leguminous seeds detection based on convolutional neural networks:Comparison of Faster R-CNN and YOLOv4 on a small custom dataset

This paper help with leguminous seeds detection and smart farming. There are hundreds of kinds of seeds and itcan be very difficult to distinguish between them. Botanists and those who study plants, however, can identifythe type of seed at a glance. As far as we know, this is the first work to consider leguminous seeds images withdifferent backgrounds and different sizes and crowding. Machine learning is used to automatically classify andlocate 11 different seed types. We chose Leguminous seeds from 11 types to be the objects of this study. Thosetypes are of different colors, sizes, and shapes to add variety and complexity to our research. The images datasetof the leguminous seeds was manually collected, annotated, and then split randomly into three sub-datasetstrain, validation, and test (predictions), with a ratio of 80%, 10%, and 10% respectively. The images consideredthe variability between different leguminous seed types. The images were captured on five different backgrounds: white A4 paper, black pad, dark blue pad, dark green pad, and green pad. Different heights and shootingangles were considered. The crowdedness of the seeds also varied randomly between 1 and 50 seeds per image.Different combinations and arrangements between the 11 types were considered. Two different image-capturingdevices were used: a SAMSUNG smartphone camera and a Canon digital camera. A total of 828 images wereobtained, including 9801 seed objects (labels). The dataset contained images of different backgrounds, heights,angles, crowdedness, arrangements, and combinations. The TensorFlow framework was used to construct theFaster Region-based Convolutional Neural Network (R-CNN) model and CSPDarknet53 is used as the backbonefor YOLOv4 based on DenseNet designed to connect layers in convolutional neural. Using the transfer learningmethod, we optimized the seed detection models. The currently dominant object detection methods, Faster RCNN, and YOLOv4 performances were compared experimentally. The mAP (mean average precision) of the FasterR-CNN and YOLOv4 models were 84.56% and 98.52% respectively. YOLOv4 had a significant advantage in detection speed over Faster R-CNN which makes it suitable for real-time identification as well where high accuracy andlow false positives are needed. The results showed that YOLOv4 had better accuracy, and detection ability, as wellas faster detection speed beating Faster R-CNN by a large margin. The model can be effectively applied under avariety of backgrounds, image sizes, seed sizes, shooting angles, and shooting heights, as well as different levelsof seed crowding. It constitutes an effective and efficient method for detecting different leguminous seeds incomplex scenarios. This study provides a reference for further seed testing and enumeration applications.

作物轮作对多年连作棉田土壤细菌群落结构的影响

新疆棉田连作问题突出,作物轮作是缓解棉田连作障碍的有效措施。通过对长年连作棉田轮作苜蓿、大豆、花生等六种作物后土壤进行细菌群落结构分析,评价六种作物对棉田土壤微生态的影响程度,筛选能够显著改善提升连作棉田土壤微生态的作物。结果表明:大豆、花生、苜蓿三种豆科作物根际的土壤细菌群落结构与棉花相似性较高,对棉田土壤细菌ACE指数、Chao1指数虽有提升但无显著差异。而番茄、玉米、甜菜三种作物对棉田土壤细菌群落结构影响较大,显著降低了棉田土壤细菌Alpha多样性及不同分类水平细菌种群的数量。在物种组成方面,变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和酸杆菌门(Acidobacteria)为土壤中优势细菌门,变形菌门在番茄根际土壤的丰度最高(58.4%),在苜蓿根际最低(40.5%);放线菌门在苜蓿根际丰度最高(15.8%),在番茄根际最低(6.5%);酸杆菌门在大豆根际丰度最高(10.2%),在番茄根际最低(5.5%)。土壤中显著差异细菌种群主要富集在苜蓿、大豆根际,但是不同作物单季轮作未对土壤中主要有益细菌种群的相对丰度产生显著影响。综合看,大豆、花生、苜蓿三种豆科作物单季轮作对棉田土壤细菌群落结构的影响较小;番茄、玉米和甜菜能够显著降低棉田土壤细菌多样性和种群数量,其中甜菜的影响作用最显著。

2种豆科牧草生产性能与营养价值比较研究

为丰富云南草田轮作中优质豆科牧草种质资源,试验对黄花鸡足豆(Ornithopus compressus L.)开展了生产性能和营养价值评价研究。结果得出,黄花鸡足豆在云南温带地区具有良好的适应性,鲜草产量为15 525kg/hm^(2),干草产量为7 091.53kg/hm^(2),两者均高于光叶紫花苕,尤其是干鲜比较后者提高了27.8%。营养成分方面,光叶紫花苕的粗蛋白含量为17.43%,比黄花鸡足豆高出了3.09%(P<0.05),而黄花鸡足豆的P含量为0.25%,显著高于光叶紫花苕(P<0.05)。黄花鸡足豆的粗纤维含量为38.39%,高于光叶紫花苕,但是差异性不显著。综合营养成分分析,黄花鸡足豆与目前大面积利用的光叶紫花苕相比,营养价值较为一致。

西藏雅鲁藏布江流域中段砂生槐不同器官C、N、P化学计量特征

理解植物各器官化学计量特征的分布格局对于揭示其养分分配策略及生态适应性具有重要意义。砂生槐(Sophora moorcroftiana)在雅鲁藏布江中游地区水土保持的功能发挥中起着重要作用,然而目前对其化学计量特征的研究尚不清楚,在很大程度上限制了人们对其生态适应性以及对气候变化响应机制的理解。基于此,本研究以雅鲁藏布江流域中段代表性灌丛砂生槐为研究对象,在不同区域设置了18个灌丛样地,分别采集叶、枝和根,并分析不同器官样品碳(C)、氮(N)、磷(P)含量及其化学计量比。结果表明:1)不同器官的C、N、P及其化学计量特征存在显著差异,C和N含量在不同器官中的分配分别表现为枝>根>叶和叶>根>枝;P含量在叶中最高,在枝和根中无显著差异。2)叶与枝中的元素含量存在极显著相关性,尤其是N和P,而根中元素与叶和枝的相关性均不强。3)枝中N-P计量幂指数为0.67,叶中为0.65,而在根中N-P关系不显著。砂生槐不同器官C、N、P化学计量特征在一定程度上符合叶片养分含量稳定假说和生长速率假说,叶片中的元素含量相对稳定且N、P含量较高。本研究结果有助于深入理解砂生槐的养分分配策略及其对环境的适应机制,并可为高原灌丛恢复和管理提供理论指导。

生物炭对紫花苜蓿/玉米间作系统氮吸收的影响

施加生物炭有利于提高土壤氮素吸收利用效率。本研究通过田间试验,明确施加生物炭对紫花苜蓿(Medicago sativa L.)/玉米(Zea mays L.)间作系统氮吸收的影响。试验共有6个处理:玉米单作(M),苜蓿单作(A),玉米/苜蓿间作(MA),间作均施生物炭(McAc),间作仅玉米施生物炭(McA),间作仅苜蓿施生物炭(MAc)。结果表明:不同间作处理土地当量比(Land equivalent ratio,LER)均大于1,McAc的LER最高;与MA相比,施加生物炭可显著提高紫花苜蓿及玉米单株地上部氮含量,且McAc的土壤碱解氮含量提高24.95%,根表面积密度增加34.23%~275.72%,进而提高了根系吸收氮素的能力。综上,施加生物炭可以提高土壤碱解氮含量和增加植物根表面积密度,提高紫花苜蓿/玉米间作氮吸收,进而提高作物产量。相比于玉米,施加生物炭对紫花苜蓿效果良好,紫花苜蓿和玉米都施加生物炭效果最好。

不同蛋白来源全营养特医食品乳剂的制备及其体外胃肠消化特性比较

为了扩展不同类型蛋白质配料在液态全营养特医食品乳剂中的应用,探究动植物蛋白在特医乳液制备及消化特性方面的差异,该研究分别选取了酪蛋白(CS)、乳清蛋白(WPI)、大豆蛋白(SPI)、豌豆蛋白(PPI)和绿豆蛋白(MPI)作为界面稳定剂制备乳液,系统探究灭菌工艺和营养成分添加对乳液性质的影响,并筛选其中热稳定的模板乳液(未添加维生素和矿物质)和特医乳液(添加维生素和矿物质)进行体外胃肠消化特性研究。CS、WPI、SPI和PPI制备的特医乳液状态良好,MPI特医乳液出现部分絮凝。灭菌后,WPI、MPI特医乳液分别发生凝胶和絮凝现象;CS、SPI和PPI特医乳液外观均匀,且制备的乳液具有较良好的稳定性,能在30 d内保持粒径和电位稳定。进一步选取CS、SPI和PPI制备的模板乳液和特医乳液进行体外消化性质分析,消化产物测试显示CS与SPI、PPI特医乳液的胃肠消化情况无明显差异,SPI和PPI的游离氨基释放量分别为21.095 mmol/L和19.524 mmol/L。该研究有助于理解不同类型蛋白配料在液态全营养特医乳剂中的应用表现,为液态高蛋白特医食品开发提供一定的技术支持。

豆类凝集素研究进展

豆类凝集素是凝集素家族中的重要成员,主要存在于各种豆科植物的种子中。豆类凝集素是一类蛋白质或糖蛋白,能够识别并结合特定的碳水化合物,对微生物具有抑制作用。此外,豆类凝集素作为一种抗营养物质,会对动物的消化道产生影响,且对动物的免疫系统产生不利影响。文章对豆类凝集素的起源和分布、纯化原理和方式、对微生物和动物的影响进行了综述,并在此基础上对豆类凝集素的应用进行了展望,以期为凝集素的深入研究和应用以及豆类饲料资源的合理利用和加工方式改进提供参考。

三江源区青甜1号与豆科饲草混播对饲草产量和品质的影响

试验探究了青甜1号与豆科饲草混播对饲草产量和品质的影响。试验将禾本科饲草青甜1号与3种豆科饲草分别混播,采用随机区组设计,设单播处理4个(A1、A2、A3、A4),混播处理6个(B1、B2、B3、B4、B5、B6),共10个处理,每个处理重复3次。结果显示:B3处理(青甜1号∶蚕豆=4.5∶1)株高、叶面积较其他处理明显更优;B5处理(青甜1号∶蚕豆=7∶1)鲜草产量最高,为41400 kg/hm^(2),较单播青甜1号(A1)显著增加了72.5%(P<0.05),B6处理(青甜1号∶饲用豌豆=7∶1)次之,鲜草产量为38500 kg/hm^(2)。禾豆混播各处理饲草的营养成分含量显著高于单播青甜1号(A1)(P<0.05),显著低于单播饲用豌豆(A2)(P<0.05)。B6处理的粗蛋白、粗脂肪、木质素和可溶性糖含量均显著高于其他混播处理(P<0.05),分别为16.10%、7.18%、8.80%和12.42%,饲用豌豆(A2)在3种豆科饲草中营养物质含量最高。隶属函数综合评价结果表明,B6处理的隶属函数值为0.817,属优,为Ⅰ级。研究表明,混播处理中的青甜1号∶饲用豌豆=7∶1时混播各项指标优于其他品种,适宜在三江源区的果洛地区推广种植。

4种豆科绿肥养分含量及其对土壤培肥效应分析

[目的]本文旨在明确在不施用化肥的情况下豆科绿肥作物体内养分含量变化及其翻压还田后对土壤肥力的影响。[方法]于2021年10月至2022年5月,通过田间试验研究紫云英、毛叶苕子、蚕豆、箭筈豌豆4种豆科绿肥的生长发育和氮、磷、钾养分含量,并分析绿肥翻压还田后对土壤养分含量的影响。[结果]不同绿肥在苗期与生育后期全氮、全磷和全钾养分含量变化趋势相似,生育后期的养分含量显著高于苗期,干物质量达1 800 kg·hm^(-2)以上,适宜翻压。在生育后期,毛叶苕子的全氮含量(3.34%)和全磷含量(0.29%)显著高于其他3种绿肥,紫云英的全钾含量(3.58%)最高,且差异显著。紫云英和毛叶苕子的氮、磷、钾养分累积量相对较高,蚕豆和箭筈豌豆相对较低。4种豆科绿肥还田,土壤pH值没有显著影响,土壤有机碳、全氮、有效磷和速效钾含量均增加,提高了2.71%~29.50%。其中紫云英还田可以显著提高土壤肥力,土壤有机碳、全氮、有效磷和速效钾含量与休耕相比分别增加了4.04%、3.40%、29.50%和8.22%。[结论]在不额外施用化肥时,种植紫云英有利于土壤肥力提升。

Computational investigation of small RNAs in the establishment of root nodules and arbuscular mycorrhiza in leguminous plants

Many small RNAs have been confirmed to play important roles in the development of root nodules and arbuscular mycorrhiza. In this study, we carried out the identification of certain small RNAs in leguminous plants(Medicago truncatula, soybean, peanut and common bean), such as miRNAs, tRFs and srRNAs, as well as the computational investigation of their regulations. Thirty miRNAs were predicted to be involved in establishing root nodules and mycorrhiza, and 12 of them were novel in common bean and peanut. The generation of tRFs in M. truncatula was not associated with tRNA gene frequencies and codon usage. Six tRFs exhibited different expressions in mycorrhiza and root nodules. Moreover, srRNA^(5.8S) in M. truncatula was generated from the regions with relatively low conservation at the rRNA 3′ terminal. The protein-protein interactions between the proteins encoded by the target genes of miRNAs, tRFs and srRNAs were computed. The regulation of these three types of sRNAs in the symbiosis between leguminous plants and microorganisms is not a single regulation of certain signaling or metabolic pathways but a global regulation for the plants to own growth or specific events in symbiosis.

香蕉间作绿肥对土壤氮转化及叶片酶活性的影响

为探明豆科绿肥与香蕉间作下的土壤氮转化及氮代谢的变化规律,本研究采用盆栽试验,设置单作香蕉(Mimosa nana)、间作白三叶草(Trifolium repens)、间作草木樨(Melilotus officinalis)、间作黑麦草(Lolium perenne)4个处理,测定不同时期的土壤养分含量及氮代谢关键酶的变化。结果表明:香蕉与豆科绿肥间作的土壤p H、有机质、碱解氮、全氮、有效磷和速效钾的含量均有不同程度的提高,同时也提高了土壤中铵态氮、硝态氮的含量,增加了土壤中氮素的净矿化速率和净硝化速率。与单作香蕉相比,间种豆科绿肥后,香蕉叶片的硝酸还原酶(NR)、亚硝酸还原酶(NiR)及谷氨酰酸合成酶(GS)的活性均有明显提高。土壤铵态氮、硝态氮与亚硝酸还原酶(NiR)、谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)间表现出显著的正相关关系。

西藏禾豆饲草混播研究进展和发展建议

混播是指将两种或两种以上牧草在同一块土地上播种的种植方式。牧草混播通过地上部分和地下部分的资源互补性,在时空生态位上发生分化,在适合的混播组合和比例下可减少种间竞争,使混播作物间产生正的种间相关作用。文章阐述了禾豆牧草混播的优势,包括提高产量和养分含量、提高氮磷养分利用效率以及水分利用效率,禾豆牧草混播具有的优势性对草地畜牧业可持续发展具有重要意义。对此,文章归纳总结了西藏牧草混播方面取得了一些研究进展和科研成果,例举了部分地区牧草混播类型和最优播种比例,最后从试验示范和技术培训、落实种植补贴和完善基础设施、撂荒地和弃耕地复耕复种等3方面提出了应用推广建议,为西藏牧草混播种植提供科学的参考依据。