Form Of Agroforestry Research Articles

Biophysical and Ecological Interactions in a Temperate Tree-Based Intercropping System

SUMMARY Tree-based intercropping is considered an excellent farming system and can contribute much to our understanding of sustainable agriculture practices. Our current research goals are to address and quantify the numerous biophysical interactions that occur at the tree-crop interface in order to enhance our understanding of the ecology of tree-based intercropping (a form of agroforestry). In 1987, the University of Guelph established a large field experiment on 30 ha of prime agricultural land in Wellington county southern Ontario, Canada to investigate various aspects of intercropping trees with agricultural crops. A variety of spacing, crop compatibility and tree growth, and survival experiments were initiated at that time, utilizing 10 tree species within the genera Picea, Thuja, Pinus, Juglans, Quercus, Fraxinus, Acer, and Populus. Two between row-spacings (12.5 m or 15 m) and two within row-spacings (3 m, or 6 m) were utilized in conjunction with all possible combinations of three agricultural crops (soybean, corn, and either winter wheat or barley). Investigations over the last decade have documented several complementary biophysical interactions. Nitrogen (N) transfer from fall-shed leaves to adjacent crops with enhanced soil nitrification as the proposed mechanism was estimated to be 5 kg N ha−1. Soil organic carbon (C) adjacent to tree rows has increased by over 1%, largely as a result of tree litterfall inputs and fine root turnover. It is estimated that intercropping has reduced nitrate loading to adjacent waterways by 50%, a hypothesized function of deep percolate interception by tree roots. We have also noticed increased bird diversity and usage within the intercropped area as compared to mono-cropped adjacent agricultural areas, and have recorded increases in small mammal populations. Earthworm distribution and abundance was also found to be higher closer to the tree rows when compared to earthworm numbers in the crop alleys. We speculate that these are indicative of major changes in the flow of energy within the trophic structure identified with intercropping systems. In light of climate change mitigation processes, C sequestration and NO2 reduction potentials in tree-based intercropping systems were studied and compared to conventional agricultural systems. The results suggest that sequestration of C was 5 times more in the former system than in the latter. Competitive interactions between trees and crops for nutrients, moisture and light were also studied. The tangible benefits that are derived from properly designed and managed tree-based intercropping systems place this land management option above conventional agriculture in terms of long-term productivity and sustainability.

Agroforestry potential in the southeastern United States: perceptions of landowners and extension professionals

The first steps in developing an agroforestry extension and training program involve compilation, synthesis, and analysis of current knowledge on existing practices. Equally important is to understand the perceptions of landowners and professionals of agroforestry as a land use option. No systematic effort has been made to assess these critical issues in the southeastern United States. Therefore, needs assessment surveys were developed following an analysis of major demographic issues that frame land use in the region and synthesis of information obtained from informal site visits and interviews with people engaged in resource and land use in the Atlantic and Gulf Coastal Plain. Surveys of extension professionals and landowners were then undertaken in the states of Alabama, Florida, and Georgia to represent the southeastern region. In addition to getting insights into the perceived benefits and concerns about agroforestry practices, the surveys indicated that the extent of alley cropping, forest farming and silvopasture practiced by landowners was less than anticipated, and that the prominence of windbreaks was overlooked by professionals. Managed riparian forest buffers or streamside management zones and windbreak technologies were the most widely used forms of agroforestry in the study area, although landowners did not recognize influence of agroforestry practices on quality or quantity of water among benefits of highest importance to them. Multistrata patio- or home gardens were also a prominent landowner-practice and acknowledged by professionals. These survey results can be useful for developing a relevant agroforestry extension and training program in the subtropical Southeast and may be of interest to agroforestry efforts in other similar settings.

The economics of agroforestry with pine and pasture in the 500 to 700 mm annual rainfall zone of Western Australia

This study mainly compares the economics of one form of agroforestry (involving the simultaneous use of land for pine sawlog, sheep, wool and hay production) with conventional agriculture (sheep and wool production) in the 500 and 700 mm annual rainfall zone of Western Australia. The region is marked by environmental problems, particularly soil and water salinity, owing to past extensive clearly of indigenous deep-rooted vegetation for agriculture. Agroforestry can be a way to control and ameliorate the problems.

Revegetation of a scalded saline discharge zone in Central Queensland. 2. Water use by vegetation and watertable drawdown

The hydrological effect of Casuarina glauca trees established on a salt pan in East Barmoya, Central Queensland, is described. The sap flow of a single (4-year-old, 5 m tall) tree was logged with the steady-state heat balance technique at about 11 L/day. The watertable adjacent to the tree was depressed by about 130 mm relative to that 10 m from the tree, and demonstrated a diurnal oscillation of about 10 mm, consistent with an evapotranspiration rate of 1 mm/day. Infiltration was rapid in the vicinity of the tree, such -- that the watertable rose quickly (about 10 mm/h) in the vicinity of the tree after rainfall events. An apparent response of the watertable to changes in barometric pressure was also noted. The density of tree planting required to halt dryland salinity on this site was estimated, and a density trial was commenced with the aim of lowering the watertable to enable the re-establishment of pasture communities between the rows in a form of agroforestry.

Agroforestry Land Use: The Concept and Practice

In Australia, the term ‘agroforestry’ is understood in a variety of ways. Although it has often been used to describe land use characterised by productive trees over pasture this is only one form of agroforestry. Recently, more expansive interpretations have arisen in which the term is seen as synomonous with ‘trees‐on‐farms’, and in some instances, rural forestation in general. This paper attempts to clarify the nature of agroforestry and stimulate interest in a potentially important rural land use.

Tree gardening and taungya on Java: examples of agroforestry techniques in the humid tropics

Agroforestry is a general concept for a land management system combining trees and agricultural crops. For application, various specific techniques can be chosen. Each of these techniques is adjusted to a specific set of environmental as well as socio-economic factors. Agroforestry cultivators or managers belonging to varying social strata and institutional groupings may practice different forms of agroforestry, even within the same general region. This is demonstrated on the basis of two contrasting types of agroforestry which are found on the Indonesian island of Java. Tree gardening or the cultivation of a wide variety of crops in a multiple-storeyed agroforestry system is an indegenous practice on private lands, while taungya or the intercropping of young tree plantations with staple crops is practiced on state forest lands. Both systems are described as to their management characteristics, past development as well as possibilities and constraints for further development. These two practices are then compared as to various attributes, like producer group, production purpose, area of cultivation, land ownership situation, structural organization of crop combinations, possibilities for improved cultivation techniques, and suitability for application in rural development for specific target groups.