A low-input cropping system has been developed at Yurimiaguas, Peru, to serve as a transition technology between shifting and continuous cultivation for acid soiln of the humid tropics. Principal features are slash-andburn clearing, rotation of acid-tolerant upland rice and cowpea cultivars, maximum residue return, no tillage, and no lime or fertilizer apoiications. When yields decline as a res...

The 4-nitrophenyl phosphate method for acid phosphomonoesterase (EC 3.1.3.2; acid orthophosphoric monoester phosphohydrolase) determination was slightly modified to increase the sensitivity and the stability of the 4-nitrophenol coloured complex in samples rich in humic substances and easily soluble organic compounds. Based on an approach used for mycorrhizal roots, the new analytical protocol ...

The inability of crop roots to penetrate subsoil layers in some Natal sandy soils and the associated low yields are the result of toxic quantities of aluminium. The phenomenon which is common in acid sandy soils in Naltal may be easily remedied by deep liming or leaching with gypsum.

the potential risk of metal accumulation in periurban agricultural areas is a matter for concern.the climate characteristics and carbonate content of calcareous agricultural mediterranean soils typical inthese areas favour metal accumulation at the surface level; however there is also a risk of potential metalmobility. our study focuses on the soil properties affecting metal mobility in these s...

One of the main factors limiting agricultural production in tropical climate regions is mainly related to the presence of exchangeable aluminum (Al) in highly weathered acid soils. Four methods of Al determination extracted with neutral 1 mol L KCl solution were evaluated: three colorimetric methods (aluminon plus ascorbic acid, and eriochrome cyanine R by FIA) and the usual titrimetric method ...

There are many remediating methods for the polluted soils but only phytoremediation is a cost effective, environmental friendly, aesthetically pleasing approach that is most suitable for many countries. The purpose of this study was to investigate the potential of native plants for phytoremediation of contaminated soils with lead, zinc, cadmium and nickel in the rangelands around National Lead ...

BC of soils (van Breemen et al., 1983). Soil acidification may be defined as the loss of ANC and does not necesIn Slovakia H input into soils is increasing because alkaline dust sarily result in the decrease of the soil equilibrium pH emissions have been reduced since 1990. Our objectives were to exam(van Breemen et al., 1983). Süsser (1987) described ine (i) the metal release in H buffer react...