Agronomy and Crop Sciences Commons^™

Threshold Dynamics Of Vegetation And Their Management Implications In A Mongolian Shrubland, Takehiro Sasaki, Asuka Koyama, Toshiya Okuro

IGC Proceedings (1977-2023)

The concept of ecological threshold has spurred important advances in understanding the nonlinear behavior of ecosystems to various disturbances (Groffman et al. 2006, Suding and Hobbs 2009). Studies on lakes, coral reefs, and arid grasslands have shown that structural attributes of ecosystems can change abruptly along a disturbance gradient (Scheffer and Carpenter 2003, Mumby et al. 2007, Sasaki et al. 2008). Yet, such nonlinear response patterns are implicitly assumed to reflect the modification of system feedbacks and interactions. We know little about mechanistic linkages between nonlinear response patterns and underlying feedback mechanisms, and the irreversibility of nonlinear …

Leaf Epidermal Descriptors Of Forage From Caatinga, Ne Brazil, Mércia V. F. Dos Santos, Osniel F. De Oliveira, Márcio V. Da Cunha, José C. B. Dubeux Jr., Alexandre C. L. De Mello, Joelma Da S. Souza, Mário De A. Lira

IGC Proceedings (1977-2023)

In the Brazilian semi-arid region, the predominant vegetation is the Caatinga, which has a diversity of plant species, some endemic and presenting forage potential. The characterization of the plant anatomy is important for animal diet studies, using a microhistological technique (Scott and Dahl 1980) for estimating the diet botanical composition from ruminant faeces. This paper determined leaf epidermal descriptors for Caatinga species using microscopic slides.

Effects Of Livestock Grazing Intensity On Reproductive Changes In Festuca Ovina L., Somaye Alidoost, Masoume Amirkhani, Mousa Akbarlou, Mansour Mesdaghi

IGC Proceedings (1977-2023)

Reproduction and re-generation strategies, whether by sexual or asexual means, are important attributes of grazed plants. The Gramineae family is the main element of rangelands, grasslands and grassland ecosystems by virtue of their seed production and distribution mechanisms, and their tolerance of environment stresses (cold, heat, drought). Festuca ovina is a highly palatable and productive plant that has been recommended for drilling and sowing in the steppe and semi-steppe rangelands of Iran. The aim of this study, which was located in the Ghorkhoud region in North-east Iran, was to investigate the effects of different grazing intensities on reproduction of this …

Persistence Of Red Clover (Trifolium Pratense L.): Relationships Between Plant Population And Forage Yield, Fernando Ortega, Andrés Quiroz, Leonardo Parra, Juan Levío, Muriel Melo

IGC Proceedings (1977-2023)

Red clover (Trifolium pratense L.) is an important forage species in temperate regions of the world; in Chile, it is a valuable resource for animal production and for the seed industry. However, the main limitation of this species worldwide is the lack of persistence related to the high mortality of plants due to a complex of multiple biotic and abiotic factors (Ortega 1996; Taylor and Quesenberry 1996). Therefore, in 1989, a red clover breeding program was started at INIA Carillanca Research Center, Chile, with the main objectives of improving the survival of plants, forage yield and persistence. Since then, …

Temporal Variations In The Carbon And Nitrogen Ecological Stoichiometry Of Lucerne, Zhennan Wang, Huimin Yang, Yuying Shen

IGC Proceedings (1977-2023)

Ecological stoichiometry has been of great help in research investigating the coupling between plant and environment (Sterner and Elser 2002). It provides some synchronized evidence to explain the response and adaptability of plants to the environment. Carbon and nitrogen ecological stoichiometry (C/N) also embraces the use efficiency of nitrogen in plants. Previous research has focused on the spatial responses of plant C/N to different environmental factors (Yang and Wang 2011). However, there is still insufficient attention on the temporal variation in C/N, in the hope that such effort will help elucidate the mechanisms underlying plant growth/regrowth. Lucerne (Medicago sativa …

Changes In The Content And Allocation Of Carbon And Nitrogen During Forage Regrowth, Huimin Yang, Zhennan Wang, Xiaoyan Zhang

IGC Proceedings (1977-2023)

Regrowth after cutting or grazing perennial grasslands sustains the production potential of forage and the persistence of grassland species. The changes in nature, content and allocation of compounds within plant parts are fundamentally correlated to the forage regrowth process (Lambers et al. 2008). These compounds are sourced from reserves and new assimilates. Carbohydrates and proteins stored mainly in the stem base and the root play an important role at the early stages of regrowth (Meuriot et al. 2004). The newly assimilated compounds include carbon from photosynthesis for the residual leaf and stem, and nitrogen absorbed by the roots …

Grass Species Population Studies In Freshwater Pools Of Sivaganga District, South India With Different Land-Use, Dorai Pandian Kannan, Zachariah Miller Paul

IGC Proceedings (1977-2023)

Vernal pools are seasonal wetlands which fill with water in the rainy season and dry down in the spring and remain desiccated throughout the summer. These extreme conditions create a unique ecosystem that supports high species diversity (King et al. 1996). Ephemeral water pools have recently received more attention where studies have monitored the vegetation dynamics as the system shifts from an aquatic and terrestrial environment (Gopal and Junk 2000; Pott et al. 2010). Landscape changes are considered important on the biodiversity aggregation of meadows (Monterio et al. 2013). The present study was carried out to analyze …

The Effect Of Exclosure Grazing On The Distribution Pattern Of Two Important Shrubs In The Central Steppe Of Iran, Anahita Rashtian

IGC Proceedings (1977-2023)

As part of a program to improve management of rangeands, research is being undertaken on the effects of grazing intensity on vegetation communities, including the response of different plant species to long-term exclosure from grazing. Species dispersion patterns can be used as valid indicators for condition assessment of rangeland ecosystems. Landsberg et al. (2002) and Riginos and Hoffman (2003) found that excessive grazing changed the structure and composition of plant communities, increasing the abundance of some species and reducing the presence of others. Heavy grazing leads to the excessive defoliation of herbaceous plants, reducing their biomass, basal cover and …

The Effect Of Exclosures On Poa Bulbosa And Determination Of Predation: A Case Study In The Nodoushan Rangelands, Central Steppe Of Iran, Anahita Rashtian

IGC Proceedings (1977-2023)

In order to undertake investigations leading to reclamation management for rangelands, information is needed on the effect of exclosures on the production and morphology of key species such as Poa bulbosa. This paper describes a comparison of some morphological and ecological characteristics of P. bulbosa when subjected to grazing or protected long-term with exclosures. The investigation was undertaken on the Nodoushan rangelands of Yazd Province, Iran.

Sward Structure Effects On Light Interception In Rotationally-Grazed Orchardgrass (Dactylis Glomerata L.), Glenn E. Shewmaker, Laura K. Hooper

IGC Proceedings (1977-2023)

Grazing managers need to know the relationship of sward height and mass to photosynthetic capacity. The aim of this study was to measure the interception of photosynthetically active radiation (PAR) and relate it to sward structure throughout the grazing season on rotationally-grazed orchardgrass/cocksfoot (Dactylis glomerata L.) pastures.

Functional Responses Of South African Rangelands In Contrasting Tenure Systems, Cristian A. Moreno García, Jürgen Schellberg, Frank Ewert, Anja Linstädter, Jan C. Ruppert, Susana B. Perelman

IGC Proceedings (1977-2023)

Land degradation in South African rangelands has frequently been studied in the context of tenure systems, because both governmental policy and range management practices were historically implemented in contrasting forms. We compared the functional response of vegetation along grazing gradients between a communal (CU) and commercial (CO) farming areas. One transect was established per farm from the waterpoint to a mid-field position. Six equally spaced plots (5 m × 5 m) were set up along each transect. Using a taxon-free sampling procedure, we recorded the response of 15 community-aggregated plant functional traits (CPFT) in: (1) mature standing biomass; and (2) …

State Of Knowledge In Tiller Dynamics, Cory Matthew, Mónica G. Agnusdei, Silvia G. Assuero, André F. Sbrissia, Omar Scheneiter, Sila C. Da Silva

IGC Proceedings (1977-2023)

Persistence of sown pastures is a concern for pastoral production worldwide. Fundamentally, when a pasture does not persist the problem can be expressed in terms of inadequate new tiller production or excessive tiller death. However, the collection of data to build an understanding of sward dynamics at this level is time consuming. Tiller survival diagrams are presented for a range of temperate and tropical grass species including Lolium perenne, Lolium multiflorum, Festuca arundinacea, Festuca pratensis, Phleum pratense, Bromus willdenowii, Cynodon dactylon, Brachiaria brizantha, Panicum maximum, Chloris gayana and Paspalum notatum. …

Grazing Management Flexibility In Pastures Subjected To Rotational Stocking Management: Herbage Production And Chemical Composition Of Kikuyu-Grass Swards, André F. Sbrissia, Valéria P. B. Euclides, Rodrigo A. Barbosa, Denise B. Montagner, Deisy A. Padilha, Gabriela T. Santos, Guilherme D. Zanini, Paulo G. Duchini, Sila C. Da Silva

IGC Proceedings (1977-2023)

Several recent papers published on tropical pastures have pointed out that under rotational stocking management regrowth should be interrupted when canopy light interception is 95% (LI). Further, these studies have revealed a positive and high correlation between LI and sward height, allowing LI management targets to be defined in terms of sward height. However, there are some indications that lower pre-grazing heights relative to those targets would result in similar leaf accumulation without interfering with sward persistence. The objective of this paper was to verify a possible flexibility of such pre-grazing height targets. A replicated experiment was conducted with treatments …

Tactical Themes For Rangeland Research, Kris M. Havstad, Deb P. C. Peters, Brandon T. Bestelmeyer, Dawn Browning, Jason W. Karl, Darren James, Scott Schrader

IGC Proceedings (1977-2023)

The problems threatening the conservation and management of rangeland, over one-half of the world’s terrestrial surfaces, are significant and growing. Current assessments of drivers and externalities shaping these problems have resulted in strategies intended to result in sustainable development of these lands and their resources. However, how can individual scientists and individual research programs support the needed strategies and goals? What can we realistically contribute and accomplish? We believe that technology can connect individual scientists and their science to the problems manifest in rangelands over the world, in a more rapid exchange than has occurred in the past. Recognition of …

Phyllochron And Leaf Lifespan Of Four C4 Forage Grasses Cultivated In A Silvopastoral System, Tiago C. Baldissera, Laíse Da S. Pontes, Raquel S. Barro, André F. Giostri, Keli C. S. Guera, Miquéias Michetti, Vanderlei P. Da Silva, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

Silvopastoral systems are emerging as an option for more sustainable land use. However, the challenge is to optimize pasture production and the determine suitable management by understanding the growth and development of forages under trees canopy (Palma et al. 2007). In the silvopastoral system, trees change the environment that forages grow, and can influence the development of plants and, consequently, the sward dynamics. For instance, the light quantity (i.e. photon flux density) and quality (e.g. changes in red: far-red ratios) can vary as a result of the tree canopy (Beaudet et al. 2011).

Phyllochron …

Botanical Composition And Nutritive Value Of Grazing Lands From Organic And Conventional Agrosilvopastoral Production Systems Of Tropical Southeastern Mexico, Claudia Delgadillo Puga, José Bernardo Sánchez Muñoz, José Nahed-Toral, Miguel Ángel Orantes Zebadua, José Luis Cruz Lopez, Mario Cuchillo Hilario

IGC Proceedings (1977-2023)

In the current situation of agriculture, organic livestock farming has been not only adapted to ameliorate undesirable impacts on environment but also it is challenged to hold or improve agricultural yields obtain-ed by conventional agriculture. In the Mesoamerican biological corridor, a region recognized with an abundant diversity, almost all animal husbandry is based on extensive grazing and traditional agrosilvopastoral systems (Nahed-Toral et al. 2009; Nahed et al. 2010). Furthermore, the conversion of natural jungle areas to new farmland through deforestation is a prevalent problem for biological conservation. Therefore, precise knowledge for suitable agriculture and livestock product-ion are needed …

Performance Of Calves Receiving By-Products Of Oil Palm During The Dry Season In An Integrated Pasture-Forestry System In Pré-Amazonic Regions Of Brazil, Xerxes M. Tosta, Rosane C. Rodrigues, Maria Elizabeth Oliveira, Jose A. C. Junior, Ivan B. M. Sampaio

IGC Proceedings (1977-2023)

The integrated farming and livestock-forestry constitutes a viable alternative for the advancement of sustainable agriculture through its influence on social and ecological processes. Silvopastoral systems are integrated systems characterised by the management of animals in an agricultural-forestry association. These systems aim to provide shade for animals, stabilize forage production for meat production and/or milk products, forestry and various other environmental services (Maurício et al. 2010). Despite the benefits mentioned, the seasonality in the production of tropical forages needs to be considered. An efficient way to avoid losses in animal production in the dry season is with the use of …

Herbage Mass, Forage Accumulation And Nutritive Value Of Brachiaria Decumbens In A Silvopastoral System, Domingos S. C. Paciullo, Carlos A. M. Gomide, Carlos R. T. Castro, Carlos A. B. Carvalho, Rogério M. Maurício, Mirton J. F. Morenz

IGC Proceedings (1977-2023)

The use of silvopastoral systems has been suggested to ensure sustainability in animal production systems because of their potential to increase soil fertility, improve forage quality, promote animal thermal comfort and provide income diversification for the producer (Paciullo et al. 2011). Nevertheless, the shade provided by trees may affect plant growth and nutritive value of forage (Sousa et al. 2010).

This study aimed to assess the impact of shading on the allocation pattern of dry matter and on herbage nutritive value, under various shading regimes, in a silvopastoral system, during both the dry and rainy seasons.

Contribution From Tree Legumes To Mixed Grass-Legume Pastures, Valéria X. De O. Apolinário, José C. B. Dubeux Jr., Mário De A. Lira Jr., Rinaldo Luis Caraciolo Ferreira, Alexandre C. L. De Mello, Diego De Lima Coelho, Everardo V. S. B. Sampaio

IGC Proceedings (1977-2023)

Legumes and associated microorganisms may fix N from atmosphere and benefit grass on mixed grass-legume pastures. Nitrogen may be transferred by different mechanisms, including direct transfer of N compounds by roots, decomposition of nodules, roots, litter from legume (Nair 1993), and through animal excreta after legume intake by cattle. Silvopastoral systems including tree legumes may become a viable option in tropical regions, considering the increasing prices of N fertilizers compared to farm products such as beef and milk.

This experiment evaluated legume contribution on mixed grass-legume pastures in the coastal region of Pernambuco State, Brazil.

Animal Performance And Pasture Characteristics Of Brachiaria Decumbens Stapf., Gliricidia Sepium (Jacq.) Steud, And Mimosa Caesalpiniifolia Benth. In Silvipastoral Systems, Alexandre C. L. De Mello, Suellen Brandão De Miranda Costa, José C. B. Dubeux Jr., Mércia V. F. Dos Santos, Valéria Xavier De Oliveira Apolinário, Fernando Tenório Filho, Marcelo Santana Meireles, Camilla Gomes Pereira

IGC Proceedings (1977-2023)

Grasslands are the major source of feed for ruminants (Zanine 2005). Seasonality of production, however, is a constraint in forage-based systems. Silvopastoril systems combine different components (animals, trees, and forages) into one integrated system and may improve forage distribution across seasons. Resource use is usually more efficient both spatially and temporally, increasing land use efficiency (Nair 1993). Tree legumes present potential for silvopastoril systems because they can fix N from the atmosphere, improve cattle diet, and lead to a faster N cycle. In addition, trees provide shade and may reduce heat stress for grazing animals in warm-climate grasslands. Legume trees …

Effect Of Defoliation Frequency On Forage Yield From Intensive Silvopastoral Systems Compared To A Monoculture Grassland, L. Sarabia-Salgado, Francisco J. Solorio-Sánchez, Fernando Casanova-Lugo, Luis Ramírez-Avilés, Juan C. Ku-Vera, Jose A. Caamal-Maldonado

IGC Proceedings (1977-2023)

Livestock production in the tropical regions of the world faces serious constraints as a result of climate change. Monoculture based pastures require the use of large amounts of nitrogen fertilizers to sustain production throughout the year. In general terms, tropical grasses are of low quality and when consumed by ruminant species, contribute to the emission of greenhouse gases (methane, carbon dioxide and nitrous oxide) (Herrero et al. 2009; Place et al. 2009). The establishment of intensive silvopastoral systems (iSPS) with associated shrubs legumes and grasses can increase the yield and quality of forage as well as fixation and transfer of …

Productive Performance Of Growing Cattle Grazing A Silvopastoral System With Leucaena Leucocephala, R. Mayo-Eusebio, M. P. Utrilla-García, C. F. Aguilar-Pérez, Francisco J. Solorio-Sánchez, A. J. Ayala-Burgos, Eduardo G. Briceño-Poot, Luis Ramírez-Avilés, Juan C. Ku-Vera

IGC Proceedings (1977-2023)

In tropical regions, the feeding of cattle is usually based on the grazing of medium to low quality grasses. Low fertility of soils, changing climatic conditions and the poor management of pastures, have further reduced the quality and forage yield of pastures. The low availability and quality of grasses gives modest weight gains for grazing cattle and this in-turn causes low economical efficiency of cattle production systems (Campos et al. 2011). Silvopastoral systems represent a sustainable option for meat and milk production in the tropics. The association of grasses with legumes such as Leucaena leucocephala (leucaena) supply forage with …

Hedges And Woody Strips Browsing By Cattle On Pasture In Wallonia, Belgium, Sophie Vandermeulen, Mathilde Pascal, Christian Marche, Arnaud Pilet, Yves Beckers, Jérôme Bindelle

IGC Proceedings (1977-2023)

Shrub and tree forages are commonly used in animal production in many regions of the world. Nonetheless, in Western Europe, and especially in Wallonia in Belgium, hedges and woody strips have disappeared from the agricultural landscape over the past 60 years. Browse species are usually rich in plant secondary compounds such as tannins whose benefits on CH4 production and intestinal parasitism have been highlighted (Ramírez-Restrepo et al. 2010). Currently, agri-environmental measures taken by the Walloon government promote hedges and woody strips in pastures, raising the interest in browse species functionalities in ruminant production.

This study aimed at: (1) determining …

Balancing Pastoral And Plantation Forestry Options In New Zealand And The Role Of Agroforestry, Grant B. Douglas, Andrew J. Wall, Michael B. Dodd, Martin F. Hawke, Ian R. Mcivor

IGC Proceedings (1977-2023)

Pastoral agriculture and forestry enterprises are key features of New Zealand’s landscape and are very important economically. They are competing landuses, particularly on moderate to steep hill country. Agroforestry involving spaced trees of Pinus radiata on pasture was developed in the 1970s to provide dual incomes from livestock enterprises and the later tree crop. In contrast, wide-spaced trees of predominantly Populus and Salix spp. are planted mainly for erosion control. Characteristics of pastoralism and plantation forestry are reviewed, including trends in conversions between these landuses. Roles, challenges and opportunities with wide-spaced trees are presented, together with current and future research …

Variation Analysis Of Root System Development In Wheat Seedlings Using Root Phenotyping System, Ekundayo Adeleke, Reneth Millas, Waymon Mcneal, Justin Faris, Ali Taheri

Agricultural and Environmental Sciences Faculty Research

Root system architecture is a vital part of the plant that has been shown to vary between species and within species based on response to genotypic and/or environmental influences. The root traits of wheat seedlings are critical for their establishment in soil and evidently linked to plant height and seed yield. However, plant breeders have not efficiently developed the role of RSA in wheat selection due to the difficulty of studying root traits. We set up a root phenotyping platform to characterize RSA in 34 wheat accessions. The phenotyping pipeline consists of the germination paper-based moisture replacement system, image capture …

Coimbatore 3 (Co3 - Pennisetum Perpureum X Pennisetum Americarnum) Grass As An Intercrop Under Coconut (Cocos Nucifera), Sharini Carol Somasiri, Sujatha Premaratne

IGC Proceedings (1977-2023)

The effect of cultivation of Coimbatore 3 (CO3; Pennisetum perpureum x Pennisetum americarnum) grass under coconut has not been researched in Sri Lanka. We examined the effect of different levels of nitrogen fertilizer and the spread of CO3 roots in the soil. CO3 root slips were cultivated under coconut in two rows with 1x2 m within and between row spacing in a Randomized Complete Block Design with three replicates. Treatments were four Nitrogen (N) levels- 0, 14, 21 and 35 kg N/ha/year. There were sixteen effective palms per treatment. CO3 bushes were harvested at 15 cm height from ground …

Productivity And Carbon Storage In Silvopastoral Systems With Pinus Ponderosa And Trifolium Spp. Plantations And Pasture On A Volcanic Soil In The Chilean Patagonia, Francis Dube, Miguel Espinosa, Neal B. Stolpe, Erick Zagal, Naresh V. Thevathasan, Andrew M. Gordon

IGC Proceedings (1977-2023)

Little information is available about carbon (C) sequestration potentials in ecosystems on Andisols of the Chilean Patagonia. This study was undertaken to measure the size of the C stocks in three predominant ecosystems: Pinus ponderosa-based silvopastoral systems (SPS), pine plantations (PPP) and natural pasture (PST), and to examine how clover (Trifolium spp.) affect tree growth and stocks of soil C. The C contents of trees and pasture were determined by destructive sampling and dry combustion. Soil samples were taken at 0-5, 5-20, 20-40 cm depths in order to determine soil C and N. For PPP and SPS, respectively, …

A Methodological Approach To Model The Grass-Tree Relationship In Quercus Suber Mediterranean Forest Ecosystems, Slim Jarradi, Mounir Louhaichi, Mohammed Qarro, Youssef Ammari, Najib Gmira

IGC Proceedings (1977-2023)

Livestock is socially and economically an important component for the livelihood of resource poor farmers in North Africa. A portion of livestock feed resources is forest rangeland. Unfortunately, the sustainability of this resource is threatened by anthropogenic pressures. In this study a number of silvo-pastoral management systems were proposed to maintain the ecosystem balance, and to cope with Mediterranean climate variability and the negative impacts of human activities and population pressure. For this reason it was important to examine the major relations within the North African forest ecosystems, which is composed mainly of Quercus suber trees. The aim of this …

Brazilian Agroforestry Systems For Cattle And Sheep, Roberto Giolo De Almeida, Carlos M. S. De Andrade, Domingos Sávio Campos Paciullo, Paulo C. C. Fernandes, Ana Clara Rodrigues Cavalcante, Rodrigo A. Barbosa, Cacilda Borges Do Valle

IGC Proceedings (1977-2023)

Agroforestry systems for animal husbandry, including integrated crop-livestock-forest systems (ICLF) are rather diversified in the five Brazilian regions. They present several technical, environmental and socioeconomic benefits. However they are not broadly adopted, mainly because of their higher complexity compared with traditional systems as well as a certain lack of understanding by farmers regarding their benefits. To change this situation, in the last five years, the Brazilian government has directed financial resources for credit as well as for research and technology transfer addressing ICLF systems, including good agricultural practices and mitigation of greenhouse gases emissions. The goal is to improve competitiveness …

Contribution Of Annual Legumes Pasture To The Cereal In Mediterranean Agriculture Systems, Carlos Ovalle, Soledad Espinoza, Alejandro Del Pozo, Viviana Barahona

IGC Proceedings (1977-2023)

The depletion of fossil fuels, the high demand of food for a constantly growing human population and, more recently, the strong expansion of biofuel crops, are causing sharp increases in the prices of fertilizers particularly nitrogen (N)(Crews and Peoples 2004; Jensen et al. 2011). Faced with this future scenario of high cost of N fertilizer, there is increasing interest in using legumes as N sources for sustainable agriculture and livestock. In the dryland (rainfed) cropping area of the Mediterranean climatic region of central Chile, bread wheat (Triticum aestivum) is predominantly grown in rotation with oats (Avena …