Does crotalaria (Crotalaria breviflora) or pumpkin (Cucurbita moschata) inter-row cultivation in restoration plantings control invasive grasses?

Alternative methods to control invasive fodder grasses are necessary to reduce the use of herbicides in forest restoration, which has been carried out primarily in riparian zones. We sought to investigate if inter-row cultivation of crotalaria (Crotalaria breviflora DC) or pumpkin (Cucurbita moschata Duschene ex. Poir) with native tree species is an efficient strategy to control invasive fodder grasses in restoration plantings. We tested five treatments in a randomized block design, namely (1) control of brachiaria grass (Urochloa decumbens (Stapf.) Webster) with glyphosate in the implementation and post-planting grass control of the reforestation, (2 and 3) glyphosate use in the implementation and inter-row sowing of crotalaria (2) or pumpkin (3), and control of brachiaria by mowing in the post-planting phase, (4 and 5) mowing in the implementation and inter-row sowing of crotalaria (4) or pumpkin (5), and control of brachiaria by mowing in the post-planting phase. Post-planting grass control was carried out four and nine months after tree seedling planting. Throughout 13 months, we evaluated the percentage of ground cover by brachiaria grass, pumpkin production, and native tree seedling mortality, height and crown cover. The exclusive use of glyphosate, without inter-row sowing of pumpkin or crotalaria showed the most favorable results for controlling brachiaria grass and, consequently, for tree seedling development. Hence, inter-row cultivation of green manure or short-lived crop species is not enough to control invasive grasses in restoration plantings, and complementary weeding is necessary to reduce the highly competitive potential of C4 grasses for supporting native species seedlings growth.

Does crotalaria (Crotalaria breviflora) or pumpkin (Cucurbita moschata) inter-row cultivation in restoration plantings control invasive grasses?

Alternative methods to control invasive fodder grasses are necessary to reduce the use of herbicides in forest restoration, which has been carried out primarily in riparian zones. We sought to investigate if inter-row cultivation of crotalaria (Crotalaria breviflora DC) or pumpkin (Cucurbita moschata Duschene ex. Poir) with native tree species is an efficient strategy to control invasive fodder grasses in restoration plantings. We tested five treatments in a randomized block design, namely (1) control of brachiaria grass (Urochloa decumbens (Stapf.) Webster) with glyphosate in the implementation and post-planting grass control of the reforestation, (2 and 3) glyphosate use in the implementation and inter-row sowing of crotalaria (2) or pumpkin (3), and control of brachiaria by mowing in the post-planting phase, (4 and 5) mowing in the implementation and inter-row sowing of crotalaria (4) or pumpkin (5), and control of brachiaria by mowing in the post-planting phase. Post-planting grass control was carried out four and nine months after tree seedling planting. Throughout 13 months, we evaluated the percentage of ground cover by brachiaria grass, pumpkin production, and native tree seedling mortality, height and crown cover. The exclusive use of glyphosate, without inter-row sowing of pumpkin or crotalaria showed the most favorable results for controlling brachiaria grass and, consequently, for tree seedling development. Hence, inter-row cultivation of green manure or short-lived crop species is not enough to control invasive grasses in restoration plantings, and complementary weeding is necessary to reduce the highly competitive potential of C4 grasses for supporting native species seedlings growth.

Environmental impact of the Brazilian Agrarian Reform process from 1985 to 2001

During the past 20 years, most settlements of the Brazilian Agrarian Reform (AR) have been established in or near better-preserved natural ecosystems, where environmental impact is likely to be negative and contribute to natural resources degradation. The objective of this work is providing a first, comprehensive insight of the impacts related to the environmental quality of these settlements, based on the primary survey of 4,340 AR settlements installed between 1985 and 2001. An index was calculated to integrate different aspects of environmental impacts in one single number. The index showed significant regional variation, with lower values (low environmental quality) for the North and Northeast of Brazil, intermediate values for the Central-west and Southeast, and high values for the South. Environmental impacts resulting from AR and settlement creation are slowly decreasing with time, but are still very high in absolute values. The lack of protection of riparian areas, cultivation of legal reserves, and deforestation, are the main concerns related to environmental impacts.

Até o presente a maioria dos assentamentos da Reforma Agrária brasileira (AR) têm sido estabelecidos em ou perto de ambientes preservados, nos quais impactos ambientais negativos são esperados e podem levar à degradação dos recursos naturais. O objetivo deste trabalho foi apresentar uma visão ampla dos impactos relacionados à qualidade ambiental dos assentamentos com base em dados primários coletados em 4.340 projetos criados entre 1985 e 2001. Um índice foi criado com a finalidade de integrar diferentes aspectos ambientais. Este índice apresentou expressiva variação regional, com valores menores (baixa qualidade ambiental) nas regiões Norte e Nordeste do Brasil, intermediários na região Centro-Oeste e Sudeste, e elevados na região Sul. Os impactos ambientais resultantes da criação de assentamentos diminuíram com o tempo, mas ainda são elevados em termos absolutos. A falta de proteção de Áreas de Preservação Permanente, o cultivo de Reservas Legais e o desmatamento são os principais fatores relacionados aos impactos ambientais.

Environmental impact of the Brazilian Agrarian Reform process from 1985 to 2001

During the past 20 years, most settlements of the Brazilian Agrarian Reform (AR) have been established in or near better-preserved natural ecosystems, where environmental impact is likely to be negative and contribute to natural resources degradation. The objective of this work is providing a first, comprehensive insight of the impacts related to the environmental quality of these settlements, based on the primary survey of 4,340 AR settlements installed between 1985 and 2001. An index was calculated to integrate different aspects of environmental impacts in one single number. The index showed significant regional variation, with lower values (low environmental quality) for the North and Northeast of Brazil, intermediate values for the Central-west and Southeast, and high values for the South. Environmental impacts resulting from AR and settlement creation are slowly decreasing with time, but are still very high in absolute values. The lack of protection of riparian areas, cultivation of legal reserves, and deforestation, are the main concerns related to environmental impacts.

Até o presente a maioria dos assentamentos da Reforma Agrária brasileira (AR) têm sido estabelecidos em ou perto de ambientes preservados, nos quais impactos ambientais negativos são esperados e podem levar à degradação dos recursos naturais. O objetivo deste trabalho foi apresentar uma visão ampla dos impactos relacionados à qualidade ambiental dos assentamentos com base em dados primários coletados em 4.340 projetos criados entre 1985 e 2001. Um índice foi criado com a finalidade de integrar diferentes aspectos ambientais. Este índice apresentou expressiva variação regional, com valores menores (baixa qualidade ambiental) nas regiões Norte e Nordeste do Brasil, intermediários na região Centro-Oeste e Sudeste, e elevados na região Sul. Os impactos ambientais resultantes da criação de assentamentos diminuíram com o tempo, mas ainda são elevados em termos absolutos. A falta de proteção de Áreas de Preservação Permanente, o cultivo de Reservas Legais e o desmatamento são os principais fatores relacionados aos impactos ambientais.