Showing papers in "Agriculture, Ecosystems & Environment in 1990"

TL;DR: In this article, a comparison of yields from organic and conventional farming systems was made, the data being obtained from three sources: a series of comparative observations; four long-term replicated field plot experiments covering a full crop rotation; the Haughley experiment, a unique comparison of three agroecosystems, one of which represented a closed system.

TL;DR: It is argued that the only remedy for agriculture in the region is increased production per unit area by the application of external inputs, which will require a changing price policy to make it economically viable, and can only be achieved through solidarity of the international community in the area of agricultural trade policies.

TL;DR: In this article, the authors found that oak and annual grassland savanna in the foothills of the Sierra Nevada, CA, soils under deciduous blue oak (Quercus douglasii ) canopies have higher nitrogen turnover and inorganic N availability than surrounding open grassland soils, as measured by seasonal changes in inorganic n pools, mineralizable N (anaerobic incubation) and nitrification potential (chlorate inhibition assay).

TL;DR: In this article, the effect of wood ash amendment on soil pH and soil test nutrient levels as measured by a pH 3, 1 M NH4OAc extractant was investigated.

TL;DR: The significance of differential abilities of VAM fungal species to tolerate edaphic conditions and to infect crop plants, as well as the significance of preferential associations and diversity of V AM fungi are presented.

TL;DR: In this article, the authors conducted experiments to determine the rate and extent of decomposition of 3 animal wastes (farmyard manure, pig slurry and poultry manure), 2 urban wastes (sewage sludge and municipal refuse compost) and one crop residue (rye straw) in a sandy loam soil.

TL;DR: In this article, mycorrhizal infection may enhance root/shoot barrier of the host plants for toxic heavy metals and may play a role in heavy metal resistance of the plants.

TL;DR: In this paper, changes in village farming systems brough about by population growth and continuing low rainfall, are described for the three main agro-ecological zones in Burkina Faso.

TL;DR: In this paper, a mass balance approach was developed using a mass-balance approach to explain the variations in the amounts of soil phosphorus (P) and sulphur (S) found across a range of slopes and aspects in four 10-ha farmlets located in summer-moist hill-country pastures in the southern North Island of New Zealand.

TL;DR: It is suggested that most plants only derive benefits at times when their demand for P is much greater than the capacity of their root systems to supply it, and flowering and seedling establishment may be examples of such times for many plants.

TL;DR: Coal fly ash was applied at rates of 0, 3, 6 and 12% to a sandy soil and a sandy loam to evaluate its effect on yields of two vegetable crops, Brassica parachinensis and B. chinensis.

TL;DR: The physical properties of desert dune sand are reviewed as part of its ecological characteristics in this article, where the problem of low and unreliable rainfall in arid lands can be turned to advantage by the use of the drip irrigation method, which allows a rational and economic use of fertilizers without the risk of leaching by subsequent rain.

TL;DR: During the growing season some plant species were mostly heavily infected (newly formed roots became almost immediately infected: especially arbuscles and coiled hyphae were present), others were sometimes infected (including some Chenopodiaceae), and few species were never infected.

TL;DR: The stimulating effect of charcoal on the infection of soybean by the indigenous VAM fungi was confirmed under these conditions but this effect was found only before the flowering stage and with low rates of P fertilizer.

TL;DR: Endogaeic species of earthworms such as Aporrectodea spp.

TL;DR: VAM showed a higher efficiency under P deficiency (FePO4) with most of the LRs than with HYVs and with MCP-fertilization differences between the reciprocal F1 indicated also plasmatic effects.

TL;DR: Ordination analysis of the data indicates that organic matter accumulation and moisture availability may be important in determining mycorrhizal population structure in Sitka spruce stand.

TL;DR: In this article, the authors measured several selected soil physical properties and plant growth indicators thought to be affected by animal trampling were measured in three experiments ranging over 8 years, including alfalfa (Medicago sativa), Bermudagrass (Cynodon dactylon), soybeans (Glycine max), and rye (Secale cereale).

TL;DR: A model that simulates the population dynamics of a weed, Sesbania punicea (Cav.) Benth.

TL;DR: In this article, a different way of describing the interaction between human society and the ecosystem is presented, referred to the society level, which provides a new perspective when assessing the energetic efficiency of farming.

TL;DR: The Segura basin finds itself in this situation as discussed by the authors, where the loss of soil in this area of SE Spain is one of the highest and most serious of the whole Iberian peninsula; in some parts it reaches 200 Tm ha−1 year−1 and in others up to 300 Tm h −1 h − 1 year− 1, which amounts to a soil thickness of ∼12 and 20 mm, respectively.

TL;DR: Non-volatile compounds released by both T. harzianum isolates growing on cellophane disks over malt agar significantly inhibited growth of Fusarium oxygsporum and Verticillium dahliae “in vitro”.

TL;DR: The endophyte is shown to be capable of mobilising nitrogen from proteins even in solutions containing phenolic compounds, and the possible ecological significance of these observations is discussed.

TL;DR: The formulation of a spore suspension into a product with a low evaporation rate could play a major role in achieving consistently effective results with C. orbiculare particularly in the western part of the range of X. spinosum.

TL;DR: In this article, the authors examined the sources of nitrates in groundwater and root zone drainage in market garden areas located on sandy soils in the Swan Coastal Plain, Western Australia, and found that NO3-N concentrations in the shallow well network ranged from 9 to 79.9 mg with a mean of 31.2 mg 1−1.

TL;DR: Hphal growth was more affected than germination by low water potentials and Mannitol was consistently more efficient than NaCl at inhibiting, both germination and hyphal growth, indicating the importance of low osmotic potentials as opposed to direct salt toxicity on the germination mechanisms.

TL;DR: Root ratings and percent stand loss showed that SCR feeding was greatest in CT systems and least in NT systems, regardless of irrigation, and NT systems had greater grain yields compared with CT systems.