Grassland Research最新文献_第10页

Impacts of fire suppression on above-ground carbon stock and soil properties in Borana rangelands, southern Ethiopia 埃塞俄比亚南部Borana牧场灭火对地上碳储量和土壤特性的影响

Grassland Research

Pub Date : 2023-04-18 DOI: 10.1002/glr2.12043

Kenea Feyisa, Sheleme Beyene, Ayana Angassa

Background

Fire is a natural disturbance that releases carbon back into the atmosphere. Pastoralists have used fire for many thousands of years for rangeland management. The use of fire in the Borana rangelands of southern Ethiopia was a common practice to improve the productivity of the rangelands. However, the use of fire as a tool to manage rangeland was prohibited by government policy in the early 1970s.

Methods

In this study, we assessed the long-term impacts of fire suppression on aboveground carbon stocks of woody and herbaceous biomass, soil organic carbon stocks, and total nitrogen stocks at burned versus adjacent unburned areas in the Borana rangelands of southern Ethiopia. The investigation was conducted in two locations: Dikale and Sanke. The upland location was represented by Dikale, while the bottomland location was represented by Sanke. Each study site was replicated three times, with burned versus adjacent unburned areas representing each replicate. Soil samples were collected in three soil depths (0–5, 5–15, and 15–30 cm), while vegetation attributes were collected from 60 plots within three burned and three adjacent unburned sites in each landscape.

Results

The soil organic carbon stock and pooled carbon stock between burned and unburned sites across the two landscapes showed minimal variation. The above-ground carbon biomass accumulation for woody and herbaceous plants did not show any significant difference between burned and unburned sites both at the bottomland and upland areas. The total nitrogen contents recorded at uplands in burned sites were significantly (p < 0.05) higher than the total nitrogen stocks for the unburned adjacent sites.

Conclusions

Burned areas accumulated relatively more carbon stocks in terms of herbaceous biomass (3.27 ± 0.43 Mg ha⁻¹) than the adjacent unburned areas (0.98 ± 0.43 Mg ha⁻¹). The results of the current study suggest that burning improved the carbon sequestration potential of herbaceous plants in arid savanna ecosystems.

背景火灾是一种将碳释放回大气的自然扰动。数千年来，牧民们一直在使用火来管理牧场。在埃塞俄比亚南部的博拉纳牧场使用火是提高牧场生产力的常见做法。然而，在20世纪70年代初，政府政策禁止将火作为管理牧场的工具。方法在这项研究中，我们评估了灭火对埃塞俄比亚南部Borana牧场燃烧区与邻近未燃烧区的木质和草本生物量地上碳储量、土壤有机碳储量和总氮储量的长期影响。调查在两个地点进行：Dikale和Sanke。高地位置由Dikale代表，而低地位置由Sanke代表。每个研究地点被复制三次，燃烧区域与相邻的未燃烧区域代表每个复制。在三个土壤深度（0-5、5-15和15-30）采集土壤样本 cm），而植被属性是从每个景观中三个被烧毁和三个相邻未烧毁地点内的60个地块收集的。结果两个景观的土壤有机碳储量和焚烧点与未焚烧点之间的合并碳储量变化最小。在低地和高地，木本和草本植物的地上碳生物量积累在燃烧和未燃烧地点之间没有任何显著差异。火烧迹地高地总氮含量记录显著（p <； 0.05），高于未燃烧的相邻位点的总氮储量。结论就草本生物量而言，焚烧地区积累了相对较多的碳储量（3.27 ± 0.43 Mg ha−1）比相邻未燃烧区域（0.98 ± 0.43 Mg ha−1）。目前的研究结果表明，焚烧提高了干旱草原生态系统中草本植物的固碳潜力。

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引用次数: 1

Feed profile analysis of oil palm-integrated beef cattle farming systems by metabolic energy budgeting and implications for beef production and pastoral system design 基于代谢能量预算的油棕榈综合肉牛养殖系统的饲料剖面分析及其对牛肉生产和畜牧系统设计的影响

Grassland Research

Pub Date : 2023-04-17 DOI: 10.1002/glr2.12044

Januarius Gobilik, Hasbudie Baco, Mohd. Azid Kabul, Suhaimi Dollah, Stephen T. Morris, Cory Matthew

Background

Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia, Malaysia and Thailand. The plantations are readily managed as silvopastoral systems incorporating cattle grazing (Oil Palm Silvopastoral System for Cattle, OPSC) but there is a need for analytical tools and data to understand system herbage supply and feed conversion efficiency (FCE).

Methods

Metabolic energy budgeting was used to estimate herbage harvested by cattle in three OPSC subsystems, 9 and 12 years after oil palm establishment, and FCE of the subsystems was determined. Understorey herbage was also analysed for nutritive value, botanical composition and herbage accumulation within one grazing-regrowth cycle.

Results

The herbage-harvested estimate was 2.0−2.4 t dry matter (DM) ha⁻¹ year⁻¹ for 9 year old subsystems and 1.4−1.7 t DM ha⁻¹ year⁻¹ for a 12 year old subsystem. Herbage metabolisable energy (ME) was 8.3−8.5 MJ kg⁻¹ DM and crude protein (CP) was 15%−16% DM. FCE values for subsystems ranged from 32 to 94 kg DM kg⁻¹ liveweight-gain.

Conclusions

Herbage DM yield is declining, while herbage ME is marginal but CP is adequate. FCE is suboptimal but can be optimised by defining the trajectory of declining herbage production with canopy closure as plantations age and matching stocking rate to herbage supply using a comparative-stocking-rate-type statistic.

背景油棕榈是一种热带作物，全球种植面积接近2000万公顷，在印度尼西亚、马来西亚和泰国有大片面积。种植园很容易作为包括放牧的森林畜牧系统进行管理（Oil Palm Silvopastoric System for cattle，OPSC），但需要分析工具和数据来了解系统牧草供应和饲料转化效率（FCE）。方法采用代谢能量预算法对油棕建立后9年和12年三个OPSC子系统的牛采草量进行估算，并测定各子系统的FCE。还分析了底层牧草在一个放牧再生周期内的营养价值、植物成分和牧草积累。结果牧草收获量估算值为2.0−2.4 t干物质（DM） ha−1 9年历史的子系统为−1年，1.4−1.7 t DM ha−1 一个12年历史的子系统为−1年。牧草代谢能（ME）为8.3−8.5 MJ kg−1 DM，粗蛋白（CP）为15%−16% 子系统的DM.FCE值范围从32到94 kg DM kg−1活重增加。结论牧草DM产量呈下降趋势，牧草ME产量较低，但CP产量充足。FCE是次优的，但可以通过定义随着种植园年龄的冠层关闭导致牧草产量下降的轨迹，并使用比较放养率类型统计将放养率与牧草供应相匹配来优化。

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引用次数: 0

Estimation of alfalfa fall dormancy using spaced plant and sward trials across multiple environments 利用不同环境下的间隔植物和草地试验评估苜蓿秋季休眠

Grassland Research

Pub Date : 2023-03-29 DOI: 10.1002/glr2.12042

Scott A. Newell, Daniel J. Undersander, Donald Viands, Julie Hansen, Steve Orloff, Daniel H. Putnam, E. Charles Brummer

Background

Alfalfa is a globally important forage crop. Cultivars are characterized by fall dormancy (FD). FD affects biomass yield and winter survival and is used to identify appropriate growing regions of cultivars. It has historically been assessed by measuring the natural height of regrowth in autumn of spaced plants in the field. Because commercial alfalfa is normally grown as a solid planted sward, FD could be different if plants were grown under real production conditions. The objective of this experiment was to assess whether FD ratings obtained from swards were similar to those obtained on spaced plants.

Methods

We evaluated 20 alfalfa cultivars in field trials established in 2015 at five locations in the United States. We harvested the trials in early autumn and measured regrowth plant height approximately 3 weeks later in 2015 and 2016.

Results

Autumn plant height responded as expected for the established check cultivars in all locations. Fall dormancy ratings for cultivars under both management systems were highly correlated.

Conclusions

Estimating FD from spaced plant height measurements in autumn is very robust, and using height data from sward plots gives equivalent results to that measured in spaced plant nurseries. This finding has many practical advantages.

背景苜蓿是全球重要的饲料作物。品种具有秋季休眠的特点。FD影响生物量产量和冬季存活，并用于确定品种的适当生长区域。历史上，它是通过测量田地里间隔植物秋季再生的自然高度来评估的。由于商业苜蓿通常是作为固体种植的草地种植的，如果植物在实际生产条件下种植，FD可能会有所不同。本实验的目的是评估从草地上获得的FD评级是否与在间隔植物上获得的评级相似。方法我们在2015年在美国五个地点建立的田间试验中评估了20个苜蓿品种。我们在初秋收获了这些试验，并在大约3周后的2015年和2016年测量了再生植株的高度。结果在所有地区，已建立的对照品种的秋季株高均符合预期。两种管理制度下品种的秋季休眠等级高度相关。结论通过秋季的间隔株高测量来估计FD是非常稳健的，并且使用草地地块的高度数据可以得到与间隔苗圃中测量的结果相当的结果。这一发现具有许多实际优势。

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引用次数: 1

Management of re-established artificial grasslands via grazing or fencing: Effects on plant and soil properties 通过放牧或围栏管理重建的人工草地：对植物和土壤特性的影响

Grassland Research

Pub Date : 2023-03-16 DOI: 10.1002/glr2.12039

Jing Cao, Yiping Chen, Yao Jiang, Jingshu Chen, Junhua Wu

Background

Revegetation is widely used in degraded grassland restoration. However, the responses of grassland plant and soil properties to fencing (FC) and grazing (GZ) remain poorly understood, especially the vegetation–soil coupling coordination (C_d) mechanism. This study explored single and interactive responses of vegetation and soil properties under FC and GZ after revegetation.

Methods

A field experiment with FC and GZ treatments was conducted in Loess Plateau reconstructed grassland, with degraded grassland as the control (CK). Plant and soil properties and C_d were analyzed using the analytic hierarchy process (AHP) and principal component analysis (PCA).

Results

The order of soil comprehensive evaluation (SCE) was GZ > FC > CK, while that of vegetation comprehensive evaluation (VCE) was FC > GZ > CK. The C_d of CK was 0.39 (mild imbalance), while the values of FC and GZ were 0.57 and 0.54, respectively (little coordination). The VCE/SCE of FC was 1.48 (soil lag type), and the values of GZ and CK were 0.69 and 0.35, respectively (vegetation lag and vegetation loss type, respectively).

Conclusions

Both GZ and FC improved C_d and facilitated recovery. However, degraded grasslands should be restored via moderate grazing for sustainable ecological and economic development.

背景植被恢复在退化草地恢复中有着广泛的应用。然而，对草地植物和土壤特性对围栏（FC）和放牧（GZ）的反应，特别是植被-土壤耦合协调（Cd）机制，仍知之甚少。本研究探讨了植被恢复后FC和GZ对植被和土壤性质的单一和交互响应。方法以退化草地为对照，在黄土高原重建草地上进行FC和GZ处理的田间试验。采用层次分析法（AHP）和主成分分析法（PCA）对植物和土壤性质以及Cd进行了分析。结果土壤综合评价（SCE）排序为GZ >； FC >； CK，植被综合评价（VCE）为FC >； GZ >； CK的Cd为0.39（轻度不平衡），而FC和GZ的值分别为0.57和0.54（少量配位）。FC的VCE/SCE为1.48（土壤滞后型），GZ和CK的值分别为0.69和0.35（植被滞后型和植被损失型）。结论GZ和FC均能提高Cd含量，促进Cd的回收。然而，退化的草原应该通过适度放牧来恢复，以实现可持续的生态和经济发展。

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引用次数: 0

Effects of sowing methods on nitrogen compounds and protease activities of whole-crop wheat silage 播种方式对全麦青贮饲料含氮化合物和蛋白酶活性的影响

Grassland Research

Pub Date : 2023-03-15 DOI: 10.1002/glr2.12041

Liuxing Xu, Guojian Tang, Dan Wu, Jianguo Zhang

Background

Whole-crop wheat (Triticum aestivum) has high nutritive value, and it has become one of the main sources of roughage for ruminants in some countries or regions. This study investigates the effects of no tillage on nitrogen compounds and protease activities of whole-crop wheat silage.

Methods

Wheat was planted on the 9th day (NB9) and 5th day (NB5) before rice harvest and on the first day after rice harvest. Sowing before harvest involved no tillage and sowing after rice harvest involved either no tillage (NA1) or conventional tillage (CK).

Results

Compared to CK, the crude protein content of NB9 and NB5 decreased by 16.4% and 9.58%, respectively. With the delay of the sowing date, the contents of non-protein nitrogen, rapidly degraded protein, and slowly degraded protein in whole-plant wheat tended to increase. Compared to NA1 wheat silage, the NH₃-N content of NB9 and NB5 silages decreased by 52.7% and 34.4%, respectively. The acid protease activity of NA1 was significantly higher than that of other treatments (p < 0.05).

Conclusions

There was no significant difference in the degree of protein degradation between NA1 and CK silages. Although the degree of protein degradation in early sowing was low, the degree of fermentation was also weak.

背景全麦（Triticum aestivum）具有较高的营养价值，已成为一些国家或地区反刍动物粗饲料的主要来源之一。研究了免耕对全麦青贮饲料中氮化合物和蛋白酶活性的影响。方法在水稻收获前第9天（NB9）、第5天（NB5）和收获后第1天种植小麦。收割前播种涉及免耕，收割后播种涉及免耕（NA1）或常规耕作（CK）。结果与对照相比，NB9和NB5的粗蛋白含量分别降低了16.4%和9.58%。随着播种期的推迟，全株小麦中非蛋白氮、快降解蛋白和慢降解蛋白的含量有增加的趋势。与NA1小麦青贮相比，NB9和NB5青贮的NH3-N含量分别降低了52.7%和34.4%。NA1的酸性蛋白酶活性显著高于其他处理（p <；结论NA1和CK两种青贮饲料的蛋白质降解程度无显著差异。虽然早播时蛋白质降解程度较低，但发酵程度也较弱。

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引用次数: 0

Leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of two C4 African grasses under simulated drought 模拟干旱条件下两种C4非洲草的叶气交换特性、生物量分配和水分利用效率

Grassland Research

Pub Date : 2023-03-02 DOI: 10.1002/glr2.12040

Kevin Z. Mganga, Jana Kuhla, Andrea Carminati, Johanna Pausch, Mutez A. Ahmed

Background

Few studies have evaluated the effect of drought on the morpho-physiological characteristics of African C₄ grasses. We investigated how drought affects leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of Enteropogon macrostachyus and Cenchrus ciliaris.

Methods

The grasses were grown in a controlled environment under optimum conditions, that is, 70% of the maximum water-holding capacity (WHC) for the first 40 days. Thereafter, half of the columns were maintained under optimum or drought conditions (30% of maximum WHC) for another 20 days.

Results

Under optimum conditions, C. ciliaris showed a significantly higher photosynthetic rate, stomatal conductance, and transpiration rate than E. macrostachyus. Drought decreased the photosynthetic rate, stomatal conductance and transpiration rate only in C. ciliaris. The net photosynthetic rate, stomatal conductance, and leaf transpiration of E. macrostachyus did not differ significantly under optimum and drought conditions. E. macrostachyus showed an increase in its water use efficiencies under drought to a greater extent than C. ciliaris.

Conclusions

Our results demonstrate that C. ciliaris is more sensitive to drought than E. macrostachyus. The decrease in the intercellular CO₂ concentration and the increase in stomatal limitation with drought in C. ciliaris and E. macrostachyus suggest that stomatal limitation plays the dominant role in photosynthesis of the studied African C₄ grasses.

背景很少有研究评估干旱对非洲C4草形态生理特征的影响。我们研究了干旱如何影响大盖肠杆菌和毛白杨的叶片气体交换特性、生物量分配和水分利用效率。方法在最佳条件下，即前40天最大持水量（WHC）的70%的条件下，在受控环境中生长。此后，将一半的柱在最佳或干旱条件下（最大WHC的30%）再维持20天。结果在最适条件下，纤毛藻的光合速率、气孔导度和蒸腾速率均显著高于巨大叶藻。干旱只降低了纤毛藻的光合速率、气孔导度和蒸腾速率。在最适和干旱条件下，大白菜的净光合速率、气孔导度和叶片蒸腾作用没有显著差异。在干旱条件下，E.macrostachys的水分利用效率比C.ciliaris的提高幅度更大。结论纤毛圆线虫对干旱的敏感性高于巨大圆线虫。随着干旱，C.ciliaris和E.macrostachyus细胞间CO2浓度的降低和气孔限制的增加表明，气孔限制在所研究的非洲C4草的光合作用中起主导作用。

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引用次数: 1

Seasonal variations in nutritive and botanical composition properties of multispecies grazing swards over an entire dairy grazing season 多种放牧草地在整个奶牛放牧季节营养和植物组成特性的季节变化

Grassland Research

Pub Date : 2023-01-20 DOI: 10.1002/glr2.12037

Ciarán Hearn, Michael Egan, Mary Bridget Lynch, Christina Fleming, Michael O'Donovan

Background

Recently, there has been increasing interest in the use of multispecies (MS) swards in dairy grazing systems.

Methods

A plot grazing study was established to investigate the potential contribution of different sward species (perennial ryegrass, legumes and herbs) sown in grazing pastures. Ten sward mixtures were sown, ranging in complexity from a perennial ryegrass (PRG) monoculture to binary mixtures including either forage legumes or herbs to a five-species mixture; four different nitrogen (N) application rates of 0, 100, 150 and 200 kg N ha⁻¹ were applied to each sward.

Results

Species abundance for all sward species components was associated with the interaction of time point and sward mixture; species abundance for all sward components, except PRG, was associated with the interaction of N application and sward mixture. The interactions of time point and sward mixture, and time point and N application rate, were associated with all analysed sward chemical components, except for sward digestibility.

Conclusions

Increased N application rates reduced the level of clover in all sward mixtures. Increased levels of white clover led to increased sward crude protein levels; the inclusion of ribwort plantain led to some seasonal variation in the nutritive value of swards.

近年来，人们对多物种草地在奶牛放牧系统中的应用越来越感兴趣。方法采用样地放牧研究方法，探讨不同禾本科牧草(多年生黑麦草、豆科植物和草本植物)在放牧草地上的潜在贡献。播种了10种禾草混合物，其复杂性从多年生黑麦草(PRG)单一栽培到二元混合物，包括饲料豆类或草本植物，再到五种混合物;每个草地分别施氮量为0、100、150和200 kg N ha−1。结果禾本科各物种组分的物种丰度与时间点和禾本科混交种的相互作用有关;除PRG外，所有禾草成分的物种丰度与施氮和禾草混合的交互作用有关。除草的消化率外，时间点与草混合物的交互作用、时间点与施氮量对草的化学成分均有显著影响。结论施氮量的增加降低了三叶草的含量。白三叶草添加量的增加导致叶片粗蛋白质水平的增加;车前草的加入导致了草的营养价值有一定的季节变化。

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引用次数: 3

Improving bermudagrass in the Southeastern United States with alfalfa as an alternative nitrogen source in grazing systems 在放牧系统中以苜蓿作为替代氮源改良美国东南部的百慕大草

Grassland Research

Pub Date : 2023-01-18 DOI: 10.1002/glr2.12038

Justin C. Burt, Lisa L. Baxter, Christopher G. Prevatt, Mary Kimberly Mullenix, R. Lawton Stewart Jr., Jennifer J. Tucker

Background

Bermudagrass (Cynodon spp.) is one of the most common perennial warm-season forages grown in the Southeastern United States. The incorporation of alfalfa (Medicago sativa) into bermudagrass pastures could serve as an alternative source of nitrogen (N) while also improving the nutritive value of the forage base.

Methods

A 2-year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018 (Year 1) and May–August 2019 (Year 2) in Tifton, GA, USA. The objective was to compare the production of alfalfa–bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BG) the application of synthetic nitrogen on forage production and stocker cattle performance.

Results

Differences were observed for average daily gain (p = 0.10), gain per hectare (p = 0.02) and stocking rate (p = 0.01), in that BGA was greatest compared to BGN and BG, which did not differ from each other. Furthermore, BGA had increased forage crude protein (p = 0.01) and total digestible nutrients (p = 0.01) compared to BGN and BG. Finally, BGA provided the greatest economic return per hectare compared to BG or BGN.

Conclusions

These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.

百慕大草(Cynodon spp.)是生长在美国东南部最常见的多年生暖季牧草之一。在百米草牧场中添加苜蓿可以作为氮素的替代来源，同时也可以提高牧草基质的营养价值。方法于2018年5月至9月(第1年)和2019年5月至8月(第2年)在美国乔治亚州蒂夫顿进行为期2年的随机完全区组设计放牧评估。目的是比较紫花苜蓿-百德草混合牧场(BGA)与百德草单作牧场(BGA)的产量和合成氮的施用对饲料生产和牛生产性能的影响。结果平均日增重(p = 0.10)、每公顷增重(p = 0.02)和载畜率(p = 0.01)存在差异，其中BGA最大，BGN和BG之间无显著差异。此外，与BGN和BG相比，BGA显著提高了饲料粗蛋白质(p = 0.01)和总可消化养分(p = 0.01)。最后，与BG或BGN相比，BGA提供了每公顷最大的经济回报。这些数据表明，紫花苜蓿-百慕大草系统可以提高动物生产性能和饲料营养价值，并为美国东南部百慕大草牧场的生产者寻找替代合成氮源的可行选择。

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引用次数: 1

Switchgrass sward establishment selection is consistent across multiple environments and fertilization levels 柳枝稷在不同环境和施肥水平下的建树选择是一致的

Grassland Research

Pub Date : 2023-01-11 DOI: 10.1002/glr2.12035

Neal W. Tilhou, Michael D. Casler

Background

Strong selection can occur during switchgrass sward establishment. Differences in establishment selection due to environment or management could provide information on genotype-by-environment variation and could influence strategies for breeding perennial grasses.

Methods

Leaf samples were collected before sward establishment and from 3-year-old swards for two breeding groups (lowland and hybrid) at three locations. Within two locations, samples were collected from paired fertilized (112 kg N ha⁻¹) and unfertilized plots. Allele frequencies from pooled DNA samples were studied through multivariate analysis of variance, genomewide trait predictions (heading date and winter survivorship), and genomically estimated breeding values (GEBVs) for individual sward survival within an independent data set.

Results

This study found only minor variations in selection due to location or management. Predicted heading dates of the hybrid population had significant changes due to fertilization and location. There were strong correlations among sward establishment survival GEBVs between growing environments (hybrid r = 0.77; gulf r = 0.97). Interestingly, this study found a small number of genotypes that were over-represented in established swards across all growing environments.

Conclusions

This study reinforces a prior report of selection during sward establishment and indicates that only a small degree of establishment selection is location-specific within these diverse growing conditions.

在柳枝稷生长过程中会发生强选择。由于环境或管理导致的生境选择差异可以提供基因型随环境变化的信息，并可能影响多年生草的育种策略。方法在3个地点采集草地建立前和3年生禾草的叶片样本，分为低地和杂交两个育种组。在两个地点，从成对施肥(112 kg N ha - 1)和未施肥地块采集样本。通过多变量方差分析、全基因组性状预测(抽穗日期和冬季存活率)以及独立数据集中个体swward存活率的基因组估计育种值(GEBVs)，研究了混合DNA样本的等位基因频率。结果本研究发现，由于地点或管理，在选择上只有很小的差异。杂交群体的抽穗期预测受施肥和位置的影响有显著的变化。不同生长环境间草种成活gebv有很强的相关性(杂交r = 0.77;海湾r = 0.97)。有趣的是，这项研究发现，在所有生长环境中，少数基因型在已建立的植物中都有过度的代表。本研究强化了先前关于草木生长过程中选择的报道，表明在这些不同的生长条件下，只有一小部分草木生长选择是特定于地点的。

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引用次数: 0

Agronomic assessment of two populations of intermediate wheatgrass—Kernza® (Thinopyrum intermedium) in temperate South America 南美温带两个中间麦草- kernza®(Thinopyrum intermedium)群体的农艺评价

Grassland Research

Pub Date : 2023-01-08 DOI: 10.1002/glr2.12032

Andres Locatelli, Lucia Gutierrez, Olivier Duchene, Pablo R. Speranza, Valentin D. Picasso Risso

Background

Kernza® intermediate wheatgrass is a perennial grain and forage crop that can provide several ecosystem services. Major research efforts focused on Kernza have taken place in high latitudes. The goal of this study was to evaluate, for the first time, the agronomic performance of Kernza in a low-latitude region with mild winters.

Methods

A KS-cycle 4 Kernza population (A) was planted in spring in Wisconsin, USA, and selected in one cycle for lower vernalization requirements, obtaining a new population (B). These two populations, at three nitrogen (N) fertilization rates, were evaluated in a full factorial, completely randomized field experiment in Uruguay over 2 years.

Results

The populations were similar in grain yields and flowering time in the 1st year, but population B had 63% lower grain yield in the 2nd year and 20% lower forage yield throughout the experiment. Increasing the N rate to 160 kg ha⁻¹ led to a 63% increase in grain yield and 28% increase in forage yield across populations. Forage yields and nutritive values were similar to those reported in the northern hemisphere. However, grain yields for both the 1st (316 kg ha⁻¹) and 2nd year (41 kg ha⁻¹) were lower due to reduced flowering and weed competition.

Conclusions

Expansion of Kernza to lower-latitude regions will require further breeding to improve reproductive performance.

Kernza®中间小麦草是一种多年生粮食和饲料作物，可以提供多种生态系统服务。主要的研究工作集中在高纬度地区。本研究的目的是首次评价克恩扎在暖冬低纬度地区的农艺表现。方法在美国威斯康辛州春季种植一个KS-cycle 4 Kernza群体(A)，在一个周期内选择较低的春化需求，获得一个新群体(B)。在乌拉圭进行为期2年的全因子、完全随机田间试验，对这两个群体在3种氮肥施用量下进行评价。结果2个群体在第1年的粮食产量和开花时间上基本一致，但种群B在第2年的粮食产量比第2年低63%，整个试验期间的牧草产量比第2年低20%。将施氮量提高到160 kg ha - 1，籽粒产量提高63%，牧草产量提高28%。草料产量和营养价值与北半球的报道相似。然而，由于开花和杂草竞争减少，第一年(316 kg ha - 1)和第二年(41 kg ha - 1)的粮食产量都有所下降。结论在低纬度地区扩展Kernza需要进一步的育种来提高繁殖性能。

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引用次数: 1