Agronomy and Crop Sciences Commons^™

A Strategic Approach To Developing The Role Of Perennial Forages For Crop-Livestock Farmers, Rick Llewellyn, Michael Robertson, Richard C. Hayes, David Ferris, Clinton K. Revell, Katrien Descheemaeker

IGC Proceedings (1977-2023)

A substantial proportion of Australian animal production from grazing comes from regions and farms where cropping is the major enterprise. Developing new and improved grazing systems for mixed farms where crop production is the major driver of farm management decisions presents a unique research and development challenge. In this paper we describe a multi-disciplinary farming-systems research approach (‘EverCrop’) aimed at improving farm profitability, risk management and environmental impacts through the development and integration of new grazing options. It has been used to analyse and target new opportunities for farmers to benefit from perennial species across dry Mediterranean-type and temperate regions …

Do Multi-Paddock Systems Increase Evenness Of Grazing At The Paddock Scale?, Robyn A. Cowley, Ian A. White, Mark H. Hearnden, Leigh Hunt, Steve P. Petty, Lindy Symes

IGC Proceedings (1977-2023)

There is ongoing debate about the benefits of multi-paddock rotationally grazed systems compared to continuous grazing (Briske et al. 2008). One of the purported benefits of high density short duration grazing is more spatially uniform defoliation. A commercial-scale trial in northern Australia (Hunt et al. 2013) compared continuously grazed paddocks to cell grazed and wet season spelled systems in newly developed paddocks. This paper reports the effect of grazing system on defoliation with distance to water through time.

Drivers Of Pasture Growth In Perennial Ryegrass Pastures In Northern New Zealand Dairy Pastures, Natalie R. Mapp, Grant M. Rennie, Warren Mcg. King

IGC Proceedings (1977-2023)

The critical importance of pasture production to New Zealand’s economic performance has been widely recognised. However, a number of critical issues have been identified that limit dairy industry growth, including sub-optimal pasture condition and poor pasture persistence. Dairy farm systems in the Waikato and Bay of Plenty provinces in the upper North Island of New Zealand are predominantly pasture-based, with a temperate climate and they represent around 30% of New Zealand’s total number of dairy farms (LIC and DairyNZ, 2012). This project was established to quantify pasture performance and identify factors that drive that performance. We established a network of …

Extending The Period Of High Feed Value In Italian Ryegrass (Lolium Multiflorum Lam.) For Grazing In The Warm Temperate Zone Of Japan, Makoto Kaneko, Yoshi-Nori Nakamura, Akihisa Yamada

IGC Proceedings (1977-2023)

Japan has widely diverse climate conditions, from subtropical in the south to boreal in the north. In warm regions of the temperate zone in the south-west, such as low-lying areas of Kyushu Island, temperate grasses only barely survive during the summer (Area V in Fig. 1). Therefore, for year-round grazing, tropical grasses and temperate grasses have been used, respectively, for summer and winter (Fig. 2). Throughout Japan, grazing is limited for cows and their calves and fattening takes place in barns. Recently, as consumer preference for meat has diversified, the demand for lean meat with less fat from grazing cattle …

Early Sowing And Irrigating Of Rape Crops In Cool Temperate Environments Boosts Forage Yield Potential, Matthew T. Harrison, Keith G. Pembleton, Richard P. Rawnsley

IGC Proceedings (1977-2023)

Forage rape is commonly grown on Tasmanian dairy farms to provide feed during periods of low pasture growth and/or low nutritive value. In these regions, forage crops are generally sown between early spring and late autumn and are commonly rainfed, though farmers may apply a single irrigation at sowing. While the effect of water availability on forage yield has been well characterised for regions in north-western Tasmania (Neilsen 2005), there is a dearth of information for other regions in Tasmania. Hence, the objectives of this study were to identify optimal sowing times for, and determine the extent to which a …

Aboveground Biomass And Soil Moisture As Affected By Short-Term Grazing Exclusion In Eastern Alpine Meadows Of The Qinghai-Tibet Plateau, China, Haibo Liu, Jianping Wu, Wen Wang, Xiaoli Jin, Zhenheng Liu, Wenhua Du

IGC Proceedings (1977-2023)

Heavy grazing substantially influences grassland vegetation and animal nutrition on the Qinghai-Tibet plateau (Guo et al. 2003). Degradation is characterized by a reduction in vegetation height, reduced ground cover decrease in species diversity (Wang et al. 2007).

The objective of this study was to determine the effects of short-term exclusion from grazing on aboveground herbage, forage nutritive value, and soil moisture in an alpine meadow in the eastern zone of the plateau. Three farms, applying different intensity of grazing over the summer months, were compared.

Performance Of Anatolian Merino And Akkaraman Lambs Fed Triticale, Hungarian Vetch Or A Mixture Of The Two Forages, Serkan Ates, Gurhan Keles, Fatma Inal, Ahmet Gunes, Mounir Louhaichi

IGC Proceedings (1977-2023)

Forages from Hungarian vetch and triticale monocultures or mixtures that can be produced with relatively low cost are important feed sources for ruminants in spring particularly in the arid and semiarid regions. The feed intake and the response of different sheep breeds (Fraser et al. 2009) to forage resources that vary in feeding value may differ. Therefore it is critical to match forage to animal and crop production needs for more efficient production in integrated crop livestock farming system.

Plant Biomass And Bovine Live Weight Changes In Mono-Specific And Mixed Pastures During The Rainy Season In Dry Tropical Mexico, Régulo Jiménez-Guillén, Adrián R. Quero-Carrillo, Pedro A. Martínez-Hernández, Alfonso Hernández-Garay

IGC Proceedings (1977-2023)

Dry tropics suffer long drought periods each year, negatively affecting the amount and digestibility of forage for cattle production. The aim of this study was evaluate different pasture types, grazed by cattle during the rainy season. Three hectares were prepared to compare: grass monoculture, Andropogon gayanus (G); a grass-legume mixture of A. gayanus and Clitoria ternatea (GL), and a grass-legume-tree mixture of A. gayanus, C. ternatea and Morus alba (GLT). Two grazing cycles (4 d grazing followed by 32 d resting; 72 d total) were completed. Three heifers (average initial weight 192 kg) grazed each experimental unit. The amounts …

Patch-Differentiation Of Vegetation And Nutrient Cycling In An Extensive Pasture System, Bettina Tonn, Anika Wirsig, Manfred Kayser, Nicole Wrage-Mönnig, Johannes Isselstein

IGC Proceedings (1977-2023)

In extensive grazing systems, ‘patch-grazing’ may lead to the development of a mosaic structure consisting of short, frequently defoliated, and tall, infrequently defoliated patches. If spatial patterns of sward structure are stable over time, this may result in a long-term differentiation of botanical composition and matter fluxes between patch types within a pasture. Patch dynamics, botanical composition and topsoil nutrient concentrations of different patch types were investigated in a long-term grazing experiment in the Solling hills, Germany, where differentiated grazing intensities have been applied for 10 years. Continuously stocked beef cattle grazed to target sward heights of 6 or12 cm …

Evaluating The Benefits Of Restricted Grazing To Protect Wet Pasture Soils In Two Dairy Regions Of New Zealand, Pierre C. Beukes, Alvaro J. Romera, David A. Clark, Dawn E. Dalley, Mike J. Hedley, David J. Horne, Ross M. Monaghan, Seth Laurenson

IGC Proceedings (1977-2023)

Many dairy farms in the Manawatu and Southland regions of New Zealand have poorly drained soils that are prone to treading damage, an undesirable outcome on grazed pastures during the wetter months of the year. Removing cows to a stand-off pad during wet conditions can reduce damage, but incurs costs. The objective of this study was to evaluate the impact of different levels of restricted grazing (from 0 to 10 hours grazing time/day for lactating cows) on pasture yield, damage and wastage, feed and stand-off expenses, and farm operating profit. A simulated farm from each region was used in a …

Combination Of Biological And Chemical Soil Tests Best Predict Maize Nitrogen Response, M. D. Mcdaniel, Daniel T. Walters, L. G. Bundy, Xiaofei Li, Rhae A. Drijber, John E. Sawyer, Michael J. Castellano, C. A.M. Laboski, Peter C. Scharf

Department of Agronomy and Horticulture: Faculty Publications

Soil tests can help optimize nitrogen (N) fertilizer rates, thereby improving farmer profitability and environmental performance. In US Midwest maize (Zea mays) production, however, most soil N tests have limited accuracy to predict N fertilizer requirements. Here we tested the individual and combined ability of 30 soil tests (12 rapid N extractions, seven biological carbon or N tests, six long-term incubation kinetic parameters, and five other routine soil tests), as well as environmental and management data, to predict maize response to N fertilizer across 56 site-years in the US Midwest. Out of 30 soil tests, and across all …

Soybean Response To Water: Trait Identification And Prediction, Shawn Jenkins

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The rising demand for soybean [Glycine Max (L.) Merrill] taken in consideration with current climatic trends accentuates the importance of improving soybean seed yield response per unit water (WP). To further our understanding of the quantitative WP trait, a multi-omic approach was implemented for improved trait identification and predictive modeling opportunities. Through the evaluation of two recombinant inbred line populations jointly totaling 439 lines subjected to contrasting irrigation treatments, informative agronomic, phenomic, and genomic associations were identified. Across both populations, relationships were identified between lodging at maturity (r = -0.58, H = 0.86), canopy to air temperature differential …

Restoring The Fire–Grazing Interaction Promotes Tree–Grass Coexistence By Controlling Woody Encroachment, Jane F. Capozzelli, James R. Miller, Diane M. Debinski, Walter H. Schacht

Department of Agronomy and Horticulture: Faculty Publications

Woody encroachment can convert grasslands and savannas to shrublands and woodlands, so understanding the processes which regulate woody encroachment is necessary to conserve or restore these ecosystems.We hypothesized that recreating the fire–grazing interaction would limit woody encroachment because focal grazing increases fuel accumulation on unburned areas and increases browsing on emergent woody plants in burned areas. This study was conducted in the Grand River Grasslands of Iowa and Missouri (USA) on 11 sites (15.4–35.0 ha). Each site was assigned to one treatment: patch-burn-graze (n = 4), with spatially discrete prescribed fires and free access by cattle (the fire–grazing interaction); graze-andburn …

Effects Of Stocking Rate On The Variability Of Ecosystem Productivity In Desert Steppe, Zhongwu Wang, Shuying Jiao, Guodong Han, Mengli Zhao, Jing Wang, Walter D. Willms

IGC Proceedings (1977-2023)

Management practices can increase biodiversity and generate corresponding compensatory effects on biomass production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how stocking rate influences variability of ecosystem productivity. Four stocking rates were compared in a completely randomized block experiment in the desert steppe of Inner Mongolia, China: non-grazed control (0 sheep/ha/mo), lightly grazed (LG, 0.15 sheep/ha/mo), moderately grazed (MG, 0.30 sheep/ha/mo) and heavily grazed (HG, 0.45 sheep/ha/mo). Aboveground net primary productivity (ANPP) was measured every August for eight consecutive years (2004-2011). ANPP decreased significantly (P < 0.05) with increasing stocking rate. Coefficients of variation for community (CV_comm) in LG and MG …

Sustainable Grazing Management For Temporal And Spatial Variability In North Australian Rangelands–A Synthesis Of The Latest Evidence And Recommendations, Peter O’Reagain, Joe C. Scanlan, Leigh Hunt, Robyn A. Cowley, Dionne Walsh

IGC Proceedings (1977-2023)

Rainfall variability is a major challenge to sustainable grazing management in northern Australia, with management often complicated further by large, spatially heterogeneous paddocks. This paper presents the latest grazing research and associated bio-economic modeling from northern Australia and assesses the extent to which current recommendations to manage for these issues are supported. Overall, stocking at around the safe long term carrying capacity will maintain land condition and maximize long term profitability. However, stocking rates should be varied in a risk-averse manner as pasture availability varies between years. Periodic wet season spelling is also essential to maintain pasture condition and allow …

Management Effects On The Vegetation Of Rangeland In The Middle Of Southern Slope Of Tianshan Mountains, Linqiao Xi, Shuqi Wu, Hui Liu, Dong Wang, Chunhui Ma

IGC Proceedings (1977-2023)

Rangeland degradation is a widespread problem and its restoration remains a major challenge. In recent years, many scientists have discussed the primary causes of over-grazing and approaches to restoration of China’s grasslands (e.g. Harris 2010; Wang and Han 2005; Lu et al. 2005). The major evidence of grassland degradation is lower plant productivity, reduced biodiversity and increase in poisonous weeds (Zhao et al. 2010), increased frequency of rodent and grasshopper infestations, and large scale dust storms (Lu et al. 2005). Restoration of these impacted ecosystems is an important and challenging task, especially in Xinjiang Province, China, …

Resource Variations Across The Landscape Mediate The Impact Of Grazing On Vegetation In Mongolian Rangeland Under High Climatic Variability, Kaoru Kakinuma, Tomoo Okayasu, Takehiro Sasaki, Undarmaa Jamsran, Toshiya Okuro, Kazuhiko Takeuchi

IGC Proceedings (1977-2023)

Assessment of grazing-induced degradation of arid and semi-arid rangelands with stochastic rainfall regimes is challenging. For the last two decades, rangeland ecologists have been discussing the relative importance of biotic and abiotic factors in controlling vegetation dynamics. According to the non-equilibrium concept, which emerged as a new paradigm to describe ecosystems in highly variable and poorly predictable environments, vegetation dynamics are driven primarily by abiotic factors such as rainfall, rather than by internal biotic regulation (e.g. grazing impact). Although a number of studies have emphasized the non-equilibrium nature of most rangelands, they have produced inconsistent results and there …

Spatial Variability And Seasonal Change Of Radioactive Caesium Concentration In Grassland Vegetation, Mikinori Tsuiki, Saaya Eguchi, Yusuke Nagata, Takeki Maeda

IGC Proceedings (1977-2023)

The damage from the Fukushima Daiichi Nuclear Power Plant caused by the Great East Japan Earthquake and tsunami on March 11, 2011 resulted in serious radioactive pollution over Eastern Japan. The distribution of radioactive fallout was largely determined by wind and rainfall patterns in March 2011. Distribution patterns were not necessarily in accordance with the distance from the nuclear power plant. In Iwate Prefecture (160 to 340 km north of the nuclear power plant), the amount of fallout of radioactive material in the southern region was greater than in the northern, but the distribution pattern was complex (Fig. 1, Tsuiki …

Graphical Analysis Of Spatio-Temporal Patterns In Forage Quality, A. Bracher, M. Böhlen, F. Cafagna, A. Taliun

IGC Proceedings (1977-2023)

Due to the highly structured topography in Switzerland, crop growth conditions vary within short distances. Differences in altitude are one of the major causes for climatic variation resulting in significant spatio-temporal effects on forage quality in terms of nutrient content and feeding value, particularly in grassland dominated regions. It is one of the goals of the Swiss feed database to support queries that visualize and quantify the temporal and spatial influence on feed quality.

Spatio-Temporal Dynamics Of Global Potential Vegetation Distributions Simulated By Cscs Approach, Qisheng Feng, Tiangang Liang, Jiexie Hong, Xiaodong Huang, Jizhou Ren

IGC Proceedings (1977-2023)

The study of Potential Natural Vegetation (PNV) has been proposed as a way to examine the impact of changes in climate on the distribution of vegetation. This study analyzes the influence of climate change in the potential vegetation distribution at global scale, using the Comprehensive Sequential Classification System (CSCS) approach to explore the changes of area, shift distance and direction for each broad vegetation category.