Life Sciences Commons^™

Morphological Characterization Of Brachiaria Germplasm, C B. Valle, B L. Maass, C B. Almeida, J.C G. Costa

IGC Proceedings (1993-2023)

Brachiaria is a grass genus native to the tropical savannas of Africa. It encompasses about 90 species, a: few of which have gained economic importance owing to their adaptation to acid soils. A study was conducted at Campo Grande, Brazil and Quilichao, Colombia, using a large Brachiaria collection assembled by CIAT in east Africa. The objectives were to describe the diversity of this germplasm and to classify the accessions in clusters based on 7 morphological characters, by applying numerical taxonomy. Principal Component and Cluster Analyses were used. Wide variation was observed among the 386 accessions of 13 different species in …

New Panicum Maximum Cultivars For Diverse Ecosystems In Brazil, L Jank, J C.G Costa, Y H. Savidan, C B. Do Valle

IGC Proceedings (1993-2023)

In 1982 a collection of 426 accessions of Panicum maximum (guinea grass) representative of its natural variability, was introduced co Brazil through a co-operative agreement with Prance. After 2 years of agronomic and morphological evaluation of this germplasm in small plots in Campo Grande, MS, 25 accessions were selected to be tested in diverse ecosystems throughout Brazil. The national network of evaluation was established in January 1988, over 7 states of the country: 2 in the humid tropics, 3 in the savannas, 1 towards the north-east coast and 1 in the subtropics. Agronomic variables studied were dry season and year-round …

Evaluation Of A Collection Of Paspalum Sp. Aff P. Plicatulum For The Cerrado Ecosystem, Brazil, J.F M. Vallis, E A. Pizarro, M A. Carvalho

IGC Proceedings (1993-2023)

The present work summarises the results of the agronomic evaluation of 42 accessions of Paspalum sp. aff. P. plicatulum, with 2 levels of fertiliser (low=pasture establishment and high=crop production) on a red-yellow latosol. Dry matter DM yield in the first 10 months from establishment ranged from 350 to 4400 kg/ha. 47 days from the start of the rainy season, estimated DMY ranged from 400 to 3700 kg/ha. DM yield accumulated during the whole wet season (October-May) ranged from 1 to 18 t/ha. The proportions of dead and green material were variable, with big differences (P<0.001) between accessions. At the end of the rainy period (122 days regrowth), the ratio ranged from 0.3:1 to 25:1 (BRA009652 and 009687 respectively). The mean Crude protein content was 10.3%:tl.21 and the mean intro DM digestibility was 49%±3.7 with a range of 16 units between accessions (40% • 56%). The germplasm tested was free of foliar diseases and insect pests, including spittlebug. Seed yield was variable, ranging from very little to 1200 kg/ha pure seed yield for the most promising accessions.

White Clover To Improve Natural Grasslands In Southern Brazil, N R. Paim

IGC Proceedings (1993-2023)

Nine white clover (Trifolium repens L.) cultivars, among them 2 bred in Rio Grande do Sul, were evaluated in association with annuai ryegrass and pensacola bahiagrass. In a plot experiment, during 4 years, 17 harvests were cut to determine lhe dry matter (DM) yield of the mixture components. The annual ryegrass produced in· the first year 1634 kg/ha OM and in the second year, by natural reseeding, only 120 kg/ha. The pensacola bahiagrass increased DM yield from 954 kg/ha in the second year to 4588 kg/ha in the fourth year without any nitrogen (N) fertilisation. The while clover …

A Comparative Review Of Soil Carbon Sequestration Methods In Brazil’S Agriculture, Skylar Cheng

Discussions

Brazil is under unique pressure to adopt sustainable agricultural practices due to its intricate biodiversity and globally dominant agricultural sector. Increasing soil degradation, agricultural land expansion, and rising levels of atmospheric carbon are nationwide concerns that require multifaceted solutions. Integrated agricultural systems, which rehabilitate soils through crop, forage, and livestock rotation as well as biochar—a carbon-rich soil amendment—can address such concerns. These sustainable farming practices improve carbon sequestration and soil fertility; however, uptake remains minimal due to environmental, economic, and policy barriers. Accordingly, this paper proposes a comprehensive model of integrated systems and biochar, in which the benefits of one …

Improvement Of Subtropical Native Grasslands With The Introduction Of Forage Species And Phosphorous Fertilizers, M N. Baby, S.B C. Lustosa, A Moraes, A.C V. Motta, R L. Stanger

IGC Proceedings (1993-2023)

The experiment took place in Guarapuava-Brazil, from May 1994 to January, 1996 to evaluate the improvement of a subtropical native grassland by the introduction of species and phosphate fertilization. It was observed that for the higher dose applied there occurred an increase over the production of dry matter and crude protein production and absorption of P and K in the plant. A response was not found to the 180 kg P2O5/ha application probably because of the high capacity of soil adsorption, the method of fertilizer application, non favorable climatic conditions and liming interference. The single superphosphate-SS application was superior to …

Root Systems In Tropical Pasture Restoration Treatments In Rondônia, Brazil, M. C. Piccolo, K. C. Augusti, C. Neill, L. Fante Junior, M. Bernoux, C. C. Cerri

IGC Proceedings (1993-2023)

Soil management can influence physical and chemical soil properties, with fundamental differences in root system development. Our objectives were to quantify carbon (C) and nitrogen (N) concentrations, dry mass and length of roots subjected to different restoration treatments of degraded pasture.

Recent Advances In Stylosanthes Research In Tropical America, Bela Grof, Celso D. Fernandes, Jaqueline R. Verzignassi

IGC Proceedings (1993-2023)

The potential of neotropical savannas is very large for pasture-based livestock systems. There are 250 million ha of well-drained lowland savannas in the American tropics. Over 200 million ha are situated in the Cerrados region of Brazil. The Cerrados support 42% of the national herd. Although these ranges support large populations of livestock, productivity is generally low. Poor nutritive value of native pastures and monospecific swards of Brachiaria spp. is the principal cause of this low productivity, especially in the dry season when these grasslands often provide no more than 60% of the animal's maintenance requirements. The best option to …

Agroecology As A Science, A Movement And A Practice. A Review, A. Wezel, S. Bellon, T. Doré, Charles A. Francis, D. Vallod, C. David

Department of Agronomy and Horticulture: Faculty Publications

Agroecology involves various approaches to solve actual challenges of agricultural production. Though agroecology initially dealt primarily with crop production and protection aspects, in recent decades new dimensions such as environmental, social, economic, ethical and development issues are becoming relevant. Today, the term ‘agroecology’ means either a scientific discipline, agricultural practice, or political or social movement. Here we study the different meanings of agroecology. For that we analyse the historical development of agroecology. We present examples from USA, Brazil, Germany, and France. We study and discuss the evolution of different meanings agroecology. The use of the term agroecology can be traced …

Slides: The Cdm Carbon Market And The Upcoming U.S. Market, Evan A. Evans

Climate Change and the Future of the American West: Exploring the Legal and Policy Dimensions (Summer Conference, June 7-9)

Presenter: Evan A. Evans, P.E., Vice President and Director of Engineering, Econergy International, Boulder, CO.

15 slides.

The Earth, Energy, And Agriculture, Tad W. Patzek

Climate Change and the Future of the American West: Exploring the Legal and Policy Dimensions (Summer Conference, June 7-9)

Presenter: Tad W. Patzek, Professor of Petroleum Engineering, University of California at Berkeley, Berkeley, CA.

13 pages (includes some color illustrations).

Contains references.