An experiment was conducted to assess the possibility of quantitatively and qualitatively enhancing fodder production on contour bunds by associating grasses and nitrogen-fixing shrubs. Treatments were pure hedges (2 rows) of a grass (Pennisetum purpureum or Tripsacum laxum) or a shrub (Calliandra calothyrsus, Leucaena diversifolia or Sesbania sesban), and mixed hedges that comprised a row of a shrub and a row of a grass. Yields of mixed hedges of calliandra-tripsacum (2.06 kg/m) and leucaena-tripsacum (1.83 kg/m) were not significantly (P > 0.05) different from those of the pure tripsacum plots (2.22 kg/m). Sesbania did not withstand repeated cutting in the second year and died out. Goats grazing tripsacum would suffer a protein deficiency relative to the availability of energy. However, the higher N content of forage from mixed calliandra-tripsacum and leucaena-tripsacum hedges would provide digestible protein levels above the maintenance requirement for goats. The implications for livestock and crop production of producing higher quality fodder from the mixed hedges are discussed. We recommend the planting of calliandra-tripsacum and leucaena-tripsacum hedges for fodder production on contour bunds in the highlands of Burundi.
Tag: contour cultivation
Increasing the scope for food crop production on sloping lands in Asia: contour farming with natural vegetative strips in the Philippines
Alternative, agroecological or low-input agricultural production systems emphasize reliance on the resources present within the farm (Altieri, 1995; Pretty, 1995). Conversely, ‘conventional’ approaches to agricultural development are characterized as depending more heavily on external inputs. Our task in this collaborative effort has been to assess the extent to which so-called alternative agriculture can contribute to increased world food production in the future. This issue is significant for those making decisions on how to invest in agricultural research, and for those involved in assisting farmers to apply that research on the land. There is reason to feel some discomfort with classifying agricultural practices into ‘alternative’ or ‘conventional’. It can be more of an ideological divide than a logical one. The dichotomy is not particularly useful either scientifically or practically since most real-world systems defy such classification. A number of the cases in Part 2 have discussed practices or combinations of practices that might be identified as being either alternative or conventional depending upon one’s point of view, or that have changed over time. The traditional rainfed systems analysed in Chapter 7 originally used local resources available to the household but now incorporate some external inputs to maintain soil fertility as population has grown, chemical fertilizer has become available and cash incomes have increased. On the other hand, some high-input conventional systems such as the irrigated rice systems considered in Chapter 16 are evolving towards alternative approaches through less pesticide use.
Contour grass strips and tillage affect corn production on Philippine steepland oxisols
Cultivated steeplands in the humid tropics require better soil management systems to meet increasing food demands. The objective of this 4-yr study was to evaluate the following four contour soil management systems for corn (Zea mays L.) production: (i) contour moldboard plowing (CP); (ii) ridge tillage (RT); (iii) natural grass barrier strips plus moldboard plowing (GCP); and (iv) grass strips plus ridge tillage (GRT). Eight successive corn crops were grown in limed and fertilized soil from 1992 through 1995. On a total land area basis (cropped area plus the area occupied by the grass strips), the 1995 mean grain yields for RT (10.8 Mg ha1) and GRT (10.3 Mg ha1) were significantly greater than yields for CP (10.0 Mg ha1) and GCP (9.6 Mg ha1). The corn grain yields for the CP and RT systems before 1995 ranged from 1.3 Mg ha1 in 1992 to 8.4 Mg ha1 in 1993, while comparable GCP and GRT yields ranged from 1.4 to 7.6 Mg ha1 Excluding the area occupied by the grass strips, the GRT system had the highest 4-yr average corn yield (7.3 Mg ha1) followed by the GCP (7.2 Mg ha1), RT (6.9 Mg ha1) and CP (6.7 Mg ha1) systems. Yields improved during the 1994 and 1995 growing seasons when the grass was not permitted to grow as tall. The combination of contour ridge tillage and contour grass strips has potential for sustaining crop productivity on highly erodible steepland soils in the humid tropics.
Rapid soil redistribution within alleys: why simple extension models for contour hedgerows may not be appropriate
Grain crop response to contour hedgerow systems on sloping Oxisols
Farming systems that minimize the rate of soil degradation and optimize food crop yields are needed to sustain soil productivity on sloping, acid, infertile soils in the humid tropics. Research was conducted on two Oxisols with slopes ranging from 22 to 30% to evaluate the performance of several contour hedgerow systems, with and without the addition of 60 kg N ha1 per crop, on rice (Oryza sativa) and maize (Zea mays L.) production. Contour hedgerows were double rows of the tree legume Gliricidia sepium (G); Gliricidia and the native grass Paspalum conjugatum (GPas); Gliricidia and an exotic fodder grass Penisetum purpureum (GPen); double rows of Penisetum (Pen); and a conventional open field (C) farming system without hedgerows. Gliricidia prunings and all crop residues were applied to the soil surface in the alleys, but Penisetum was harvested. Food crop yields in all hedgerow treatments tended to be less than the Control for the first two years, presumably due to the displacement of land planted to the food crop. In the third and the fourth years, the rice and maize yields of Treatments G and GPas exceeded the Control, most consistently when N was not applied. Penisetum reduced food crop yields regardless of N application presumably due to nutrient removal in the fodder. The results indicate that Gliricidia in a contour hedgerow increases food crop yield on strongly acid Oxisols by recycling nutrients and partially supplementing the N demand by the food crops
A landscape / lifescape approach to sustainability in the tropics: the experience of the SANREM CRSP at three sites
The Sustainable Agriculture and Natural Resource Management Collaborative Research Support Program (SANREM CRSP), funded by U.S. AID, aims to develop principles and methodologies for achievement of sustainable ecosystem management at the watershed and landscape scale. In contrast to much of the earlier literature in environmental, agricultural, and ecological science which portrays humans as the despoilers of ecosystems, the SANREM approach acknowledges the role of people as integral actors who must be directly engaged in sustainable development if it is to be successful. The SANREM approach, therefore, uses an interdisciplinary, farmer-participatory research, training and information exchange strategy to bridge between scientific knowledge and local expertise in the resolution of problems. A landscape ecology approach is used to describe and understand the complex internal, external, and interactive processes within and between the individual ecosystems of a toposequence transecting two or more agroecological zones. Coupled with the landscape notion is that of “lifescape”, or the human dimension, which includes economic, cultural and social aspects in interaction with the physical and biological dimensions of ecosystems. Interventions appropriate to the local farm community members are designed and evaluated in concert with the ultimate users who are involved in all steps of the research process. The approach includes emphasis on collaboration between biological and social scientists and development practitioners in the U.S. and host countries. It also strives for interinstitutional collaboration that involves private and public institutions from each country as well as the U.S. The SANREM project is considered one of the first of its kind, a pioneering effort to solve complex natural resource and sustainable agriculture problems involving a wide range of stakeholders who may have conflicting interests among themselves. These stakeholders include local communities, international research and development organizations, U.S. universities, host country universities and government agencies, local government and nongovernment organizations (NGOs). Also, there is a need to address experimentally a hierarchical range of spatial and temporal scales across a landscape. In attempting to meet these challenges, we have many successes, many failures and many lessons learned. This chapter outlines the experiences of SANREM at the core sites in the Philippines, Burkina Faso, and Ecuador, and presents critical lessons learned in implementing a large landscape-scale research and education program