Preliminary results have been obtained on the development of 11 types of grasses with average height varying from 0.70 to 1.15 m and from 11 other types with average height from 1.30 to 5.00 m. From plots with an area of 25 m², from the collection of useful plants of the Soil Conservation Department of the Instituto Agronômico de Campinas, one sample of the plants was taken for each plot the sampled area being of 0,50 and 1.00 m², for the grasses of medium and large size, respectively. The above-ground parts of the plants were cut at the heights of 80, 26, 8, 2 and 0 cm (ground level) respectively and determinations were made of the weight and volume of each portion of the plants under investigation. The results obtained are presented in tables 1 to 3. The underground parts of the grasses were studied in the same areas where the aerial parts were cut. Blocks of soil were taken with depths of 2, 8, 26 and 80 cm. The underground portions of the plants in each block were separated by the dry method, using wire screen, their weight and volume being determined (table 1 to 3). The soil particles holding capacity of each species of grass was determined by adding to the weight of the above-ground part at the lowest cut (block Aa) the weight of the underground portion found at the first block (block Ba, table 2 and 3). It has been observed that among the medium sized grasses the capim chorão (Eragrostis curvula Nees var. valida Stapf), capim de boi (Setaria poiretiana Kunth), capim Araguai (Paspalum fasdculatum Willd.) and capim de planta (Panicum purpurascens Raddi) and among the taller grasses the capim sempre-verde (Panicum maximum Jacq. var. gongylodes), capim elefante Merker, Napier and AxB (Pennisetum purpureum Schum.) as well as capim vetiver (Vetiveria zizanioides Nash), seem to be more promissing for holding the soil particles and more useful for soil conservation purposes.

O autor descreve, neste trabalho, investigações realizadas sôbre as caraterísticas de cobertura e fixação do solo, de dez espécies vegetais. A técnica e o método que empregou consistiram, em síntese, em fazer cortes da parte aérea e em escavar blocos de terra com raízes a determinadas alturas e profundidades, numa área de 0,25 m², de forma a obter a densidade de cobertura do solo pela parte aérea e de travamento pela parte subterrânea, a diferentes distâncias da superfície do solo. Os resultados obtidos levaram às seguintes conclusões preliminares : a) A espécie Paspalum notatum Flügge, compreendendo duas variedades - grama Batatais de fôlha larga e grama Americana de folha estreita, apresentou a maior percentagem em pêso e volume da parte aérea e subterrânea a 2 e 8 centímetros, acima e abaixo do nível do solo. b) A grama das Roças (Paspalum dilatatum Poir.) oferece boa cobertura, mas o efeito de travamento é fraco para tôdas as profundidades, c) O capim Kikuiu (Pennisetum clandestinum Chio v.), a grama Tio Pedro (Paspalum convexum H. B.) e o capim Gengibre (Paspalum maritimum Trin.) proporcionam boa cobertura e sofrível travamento do solo. d) A grama Sêda (Cynodon dactylon Pers.) e a grama Portuguêsa (Panicum repens L.) deram dados satisfatórios para tôdas as alturas e profundidades, e) A Margaridinha (Wedelia paludosa L.) possibilita ótima cobertura e bom travamento a tôdas as profundidades, f) O Kudzu comum (Pueraria thumbergiana Benth.) forneceu dados bem elevados, mesmo para o último bloco subterrâneo, que atinge 80 centímetros de profundidade. Em face dos dados obtidos, o autor faz considerações sôbre a utilização das vegetações estudadas em práticas conservacionistas de caráter vegetativo

This paper describes the investigations carried out and the methods employed to determine the characteristics of ten plant species for use in various aspects of soil erosion control. Seed of the ten plant species to be studied were sowed in beds. After a suitable period of time for growth of the plants, sample areas 0.25 sq. mt. were selected. The number of plants and total volume and weight of the plant growth at specific levels (0-2 cm, 2-8 cm, 8-26 cm, 26-80 cm) both above and below ground were measured. The results obtained have led to the following preliminary conclusions. Of the plants studied the species Paspalum notalum Flügge, composed of two varieties, large leafed Batatais and Bahia grass, were found to have the largest volume and weight of plant growth in the area 2 to 8 centimeters above and below the soil surface. Roças grass (Paspalum dilatatum Poir) proved to be a good ground cover but root penetration and development was relatively poor at all depths. The Kikuiu grass (Pennisetum clandes-tinum Chiov.), Tio Pedro grass (Paspalum convexum H. B.) and Gengibre grass (Paspalum maritinum Trin.) produced a good ground cover but root development in the soil was only fair. The Bermuda grass (Cynodon dactylon Pers.) and Portuguêsa grass (Panicum repens L.) gave measurements of volume and weight of plant growth at all levels both above and below ground which indicated that these plants would be relatively satisfactory in erosion control work. The data obtained from the study of Margaridinha (Wedelia paludosa L.) indicated this species is very good both from standpoint of a cover crop and in its capacity to hold the soil in place. The common Kudzu (Pueraria thumbergiana Benth.) gave measurements of top and root development that show that it is a very good species. The author discusses in a general way all of the above mentioned species in relation to specific uses in soil conservation.