Plant production is essentially dependant on culture medium and conditions. Vegetable crops are known to grow in soil which, in natural conditions, acts as a mineral nutrient reservoir, but the soil itself is not essential to plant growth. Plant roots are able to absorb the mineral nutrients of the soil dissolved in water. When the required mineral nutrients are introduced into artificially syn...

Plants must develop efficient root architectures to secure access to nutrients and water in soil. This is achieved during plant development through a series of expansion and branching processes, mostly in the proximity of root apical meristems, where the plant senses the environment and explores immediate regions of the soil. We have developed a new approach to study the dynamics of root merist...

Vermicomposts, which are produced by the fragmentation of organic wastes by earthworms, have a fine particulate structure and contain nutrients in forms that are readily available for plant uptake. In greenhouse trials, the growth of marigold and tomato seedlings, in a commercial horticultural potting medium (Metro-Mix 360), was enhanced significantly upon substitution of Metro-Mix 360 with 10 ...

The carbon-conserving nature of reduced or no-till soils as compared to conventionally tilled soils is well document­ ed (Blevins et al., 1983; Havlin et al., 1990; Wood and Edwards, 1992). With no-till, plant residues remaining on the soil surface decompose more slowly, resulting in more carbon (C) being retained in the soil than when residues are in­ corporated into the profile (Holland and C...

The failure of a tailing pond dam at the Aznalcóllar pyrite mine (SW Spain) in April 1998 released a toxic spill affecting approximately 4300 ha along the Agrio and Guadiamar valleys. Two years later, we have studied yield and concentration of mineral nutrients and trace elements in sunflower plants grown in the spill-affected soil, and in an adjacent unaffected soil as comparison. The study ha...

Nutrient leaching in highly weathered tropical soils often poses a challenge for crop production. We investigated the effects of applying 20 t ha biochar (BC) to a Colombian savanna Oxisol on soil hydrology and nutrient leaching in field experiments. Measurements were made over the third and fourth years after a single BC application. Nutrient contents in the soil solution were measured under o...

Although it is increasingly being recognized that roots play a key role in soil carbon (C) dynamics, the magnitude and direction of these effects are unknown. Roots can accelerate soil C losses by provisioning microbes with energy to decompose organic matter or impede soil C losses by enhancing microbial competition for nutrients. We experimentally reduced belowground C supply to soils via tree...

Cultivation of sugarcane for bioethanol is increasing and the area under sugarcane is expanding. Much of the sugar for bioethanol comes from large plantations where it is grown with relatively high inputs. Sugarcane puts a high demands on the soil because of the use of heavy machinery and because large amounts of nutrients are removed with the harvest; biocides and inorganic fertilizers introdu...

The relative importance of the various pedological, climatological and physiological factors contributing to the short stature of tropical montane cloud forest (TMCF) is not well understood. This study endeavours to elucidate the controls on carbon assimilation and productivity, which, in conjunction with differences in carbon allocation, interact synergistically to reduce canopy height relativ...