Soil structure is often said to be the key to soil productivity since a fertile soil, with desirable soil structure and adequate moisture supply, constitutes a productive soil. Soil structure influences soil water movement and retention, erosion, crusting, nutrient recycling, root penetration and crop yield. The objective of this work is to study humic acid (HA) application on some physical and...

It has been hypothesized that as soil fertility increases, the amount of carbon allocated to below-ground production (fine roots) should decrease. To evaluate this hypothesis, we measured the standing crop fine root mass and the production of fine roots (<2 mm) by two methods: (1) ingrowth cores and, (2) sequential soil coring, during 2.2 years in two lowland forests growing on different soils ...

Earthworms mix soil layers and incorporate organic matter into the soil. This mixing allows the dispersion of the organic matter through the soil and makes the nutrients held in it available to plants and improves the fertility of the soil. Earthworms when present improve the soil physical, chemical and biological properties and acts as soil conditioner. They do so by fragmentation, aeration, b...

this experiment was carried out to investigate the effect of plant density on growth and seed yield of wheat (kodasht cultivar) under saline soils and rainfed condition inanbarolum region of golestan province in 2008-09. an experiment was conducted in three fields with different salinities (6.73, 9.34 and 11.63 ds m-1) based on randomized complete blocks design. treatments were four plant densi...

Worm infections caused by Soil Transmitted Helminth (STH) in Indonesia cause diarrhea, malnutrition, and malaise. One of the epidemiology STH occurs through soil or fertilizer contaminated with vegetables. Therefore, it is necessary to examine identify vegetables, especially cabbage basil. The purpose this study was determine eggs vegetables from (Brassica oleracea) basil (Ocimum basilicum) tak...

While bitter manioc has been one of the most important staple crops in the central Amazon for thousands of years, there have been few studies of its cultivation in the fertile whitewater landscapes of this region. Anthropological research on bitter manioc cultivation in the Amazon has focused almost exclusively on long-fallow shifting cultivation in marginal upland areas of low soil fertility. ...

The existence of an anthropogenic and carbon (C) enriched dark soil in different parts of the world and especially in Amazonia (Amazonian Dark Earths (ADE) or Terra Preta de Índio) proves that the predominant Ferralsols and Acrisols can be transformed into fertile soils. Charcoal formation and deposition in soils seems to be a promising option to transfer an easily decomposable biomass into ref...

Smallholder farmers in the Guinea savanna practise cereal-legume intercropping to mitigate risks of crop failure in mono-cropping. The productivity of cereal-legume intercrops could be influenced by the spatial arrangement of the intercrops and the soil fertility status. Knowledge on the effect of soil fertility status on intercrop productivity is generally lacking in the Guinea savanna despite...

Six cultures of Microsporum amazonicum were recently isolated from the hair of six spiny rats (Proechimys guyannensis) trapped near the city of Belém, Brasil. When the six isolates were paired with each other in ali possible combinations on soil-hair plates, eight of 15 pairs developed fertile ascocarps. Based on the morphology of the gymnothecia, the perfect state was classified in the genus N...

As a domain of application and reference for the proposed approach, we focused on Constructionism, a theory that studies the use of technology in the creation of educational environments. The most well known pragmatic result of Constructionism is the Logo programming language which, for the past 20 years, has been used by millions of students as a fertile soil for the development of critical re...