Studies on the Allelopathic Effects of Some Agroforestry Tree Crops

Suresh, K.; Vinaya, R. S.

doi:10.1080/01435698.1987.9752816

Cited by 36 publications

(15 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The creation of closer nutrient cycles and increases of carbon inputs into the soil through perennial root systems are among the major reasons for integrating trees into cropping systems in agroforestry (Young, 1989). However, the role of tree root systems is ambiguous: in some situations they may depress crop yields by root competition for water and nutrients Rao et al, 1991;Singh et al, 1989) and possibly allelopathic effects (Inostrosa and Fournier, 1982;Suresh and Vinaya Rai, 1987). When designing agroforestry systems, all of these possible effects of tree roots must be taken into consideration; however, in spite of major efforts into tree root research in agroforestry in recent years (Dhyani et al, 1990;Jonsson et al, 1988;Ruhigwa et al, 1992), the effects of tree roots on soils and associated crops in agroforestry associations are still poorly understood.…”

Section: Introductionmentioning

confidence: 99%

Root length dynamics in agroforestry with Gliricidia sepium as compared to sole cropping in the semi-deciduous rainforest zone of West Africa

Schroth

Zech

1995

Plant Soil

View full text Add to dashboard Cite

Tree root systems may improve soil fertility through carbon inputs, uptake of leachable nutrients and maintenance of soil biomass, but can at the same time reduce crop yields by competition for water and nutrients. Quantitative information about the positive and negative effects of tree roots and their changes in space and time are necessary for the optimization of agroforestry associations. An alley cropping experiment was layed out as a randomized complete block design on a Plinthic Lixisol/Ferralic Cambisol with Gliricidia sepium hedgerows at 5 m distance, including a sole cropping control. The development of root systems was monitored by sequential soil coring (eight samplings) during one year, with maize and groundnut as crops. Additional information is presented from a single sampling for rice during the foregoing year. Pronounced fluctuations of live root length density indicated an important variability in the nutrient and water uptake capacity of the vegetation. At low total root length density, the hedgerows affected the root development in the agroforestry plots directly by the presence of their root systems. At high root length density, they affected root development mainly by improving crop root growth and influencing the composition of the spontaneous vegetation. The root length density of the hedgerows was too low to compete with the crops for soil resources. The hedgerows tended to increase root length densities in the subsoil when few roots were present, thus possibly reducing the risk of nutrient leaching. However, the length density of the perennial root systems decreased during the cropping season, presumably as an effect of repeated pruning, and attained minimum values almost at the same time as the crops. Trees with denser root systems which are less frequently pruned may be more efficient in achieving closer nutrient cycles, though at the cost of higher root competition with crops.

show abstract

Section: Introductionmentioning

confidence: 99%

Root length dynamics in agroforestry with Gliricidia sepium as compared to sole cropping in the semi-deciduous rainforest zone of West Africa

Schroth

Zech

1995

Plant Soil

View full text Add to dashboard Cite

show abstract

“…Understorey suppression by Eucalyptus spp., especially in drier climates, has been attributed to allelopathic extracts from foliage, leafand bark-litter (May and Ash 1990). In glasshouse experiments, watering seedlings with Eucalyptus tereticornis leaf-leachates reduced growth and survival of sorghum, cowpea and sunflower crops (Suresh and Rai 1987). Despite these negative interactions, trees also indirectly facilitated recruitment through provision of leaf-litter (approx.…”

Section: Discussionmentioning

confidence: 98%

Microsite and litter cover effects on soil conditions and seedling recruitment in a saline agricultural system

et al. 2011

View full text Add to dashboard Cite

Successful revegetation of saline land is dependent on seedling recruitment to maintain vegetative cover for lowering of saline water tables and agricultural production. This paper examines seasonal effects of tree/shrub microsites and leaf-litter on soil conditions and seedling recruitment in a saline grazing system planted with Eucalyptus sargentii Maiden tree rows (15 years old) and saltbush (Atriplex spp.) interrows (8 years old). Salt bush rows were also slightly mounded. As litter accumulation decreases with increased distance from tree rows, soil conditions and seedling recruitment were compared between paired bare and litter-covered zones within three microsites: tree row, saltbush row 1 (saltbush row closest, viz. 3-4 m, to tree row) and saltbush mid-row (middle row of saltbush between adjacent tree rows, viz. 7-9 m from trees). Microsite facilitation in winter was negligible due to moderate temperatures and high water availability. However, in warmer months, saltbush mid-row microsites were most favourable for recruitment. Tree microsites inhibited recruitment through increased salinity, water repellency and potential root competition. Despite negative interactions within the tree row, trees indirectly facilitated recruitment through litter provision in saltbush rows. Overall, litter increased seedling densities through amelioration of soil temperatures and salinity. Litter reduced salinity (top 2 cm) in warmer months, from 'severe' where only halophytes survive, to 'moderate' where growth of non-halophytic species is possible, but at reduced rates. Recruitment was influenced by microsite characteristics including, litter quantities, mounding and row position.

show abstract

“…Some species currently used in multi-storey cropping (40) systems reportedly have allelopathic properties. For example, seed germination, root length and dry matter production of cowpea were depressed by aqueous leaf extracts of leucaena and when grown in leucaena top soil (98). Results of no significant effect of leucaena soil and decomposed leaf extracts on the germination of rice have also been reported (49).…”

Section: Current Status Of Researchmentioning

confidence: 91%

“…This fmding contradicts the results of laboratory studies (50) where extracts of fresh leucaena leaves inhibited rice seed germination. The germination and growth of greengram, blackgram, cowpea, pigeonpea, cowpea, soybean, sorghum, sunflower, wheat, pea, maize and mustard were inhibited by litter extracts and top soil of Casuarina equisetifolia (43,97,98). Significant reduction in ground cover was noticed under Albizzia lebbeck (7).…”

Section: Current Status Of Researchmentioning

confidence: 91%

Prospects of allelopathic research in multi-storey cropping systems

John¹,

Nair²

2000

Allelopathy in Ecological Agriculture and Forestry

View full text Add to dashboard Cite

The necessity to intensify agricultural land use has led to the development of multistorey cropping and crop mixtures. The crop combinations in two most intensive multistorey cropping systems practised World wide viz., plantation crop-based systems and homestead agroforestry system have been reviewed in this paper. In the past, much work on allelopathic interactions has been conducted in agriculture and forestry but studies in multi-storey cropping systems are limited. The study of allelopathic interactions in multi-storey cropping systems is highly complicated, owing to the species diversity and interferences arising from competition between different components of the system. This is further complicated by the unique microclimatic and edaphic factors of each system. Allelopathic research in these multi-storey cropping systems demands a multidisciplinary systems approach in which the different biological components of the system viz., microclimate, soil properties, microflora, spatial and temporal dimensions etc., should be investigated in totality. Considering the complexity of allelopathic interactions in multi-storey cropping systems, the thrust areas for allelopathic research are: separating allelopathic interference from competition, screening germplasm of crops/trees for suitability to these systems, monitoring the production of allelochemicals by the different components in relation to the microclimatic and edaphic factors of the system, exploitation of allelopathy for improving the productivity of the system and plant protection.

show abstract

Studies on the Allelopathic Effects of Some Agroforestry Tree Crops

Cited by 36 publications

References 6 publications

Root length dynamics in agroforestry with Gliricidia sepium as compared to sole cropping in the semi-deciduous rainforest zone of West Africa

Root length dynamics in agroforestry with Gliricidia sepium as compared to sole cropping in the semi-deciduous rainforest zone of West Africa

Microsite and litter cover effects on soil conditions and seedling recruitment in a saline agricultural system

Prospects of allelopathic research in multi-storey cropping systems

Contact Info

Product

Resources

About