Shrub encroachment in arid and semiarid rangelands, a worldwide phenomenon, results in a heterogeneous landscape characterized by a mosaic of nutrient-depleted barren soil bordered by nutrient-enriched shrubby areas known as ‘‘fertile islands.’’ Even though shrub encroachment is considered as a major contributor to rangeland degradation, little is known about mechanisms favoring the reversibili...

Most of the upper layer of the earth’s terrestrial crust is or has been influenced by plant roots, so most soil is actually rhizosphere soil at one time or another. Through their physical, chemical, and biological interactions with the soil, roots play a major role in soil formation (Jenny, 1941) and soil function (Wardle et al., 2004). Microbes factor prominently in global nutrient and energy ...

This study had three main objectives: (1) to evaluate the aboveground biomass and volume yield of three unrelated hybrid poplar clones in 9 year-old riparian buffer strips located on four farms of southern Québec, Canada; (2) to compare yield data at 9 years with previous data (at 6 years); (3) to evaluate how soil fertility, measured using three different soil testing methods (soil nutrient st...

A field study was initiated in 1992 to investigate the long-term impacts of beef feedlot manure application (composted and uncomposted) on nutrient accumulation and movement in soil, corn silage yield, and nutrient uptake. Two application strategies were compared: providing the annual crop nitrogen (N) requirement (N-based rate) or crop phosphorus (P) removal (P-based rate), as well as a compar...

Exogenous organic acids are beneficial in protecting plants from the stress of heavy metal toxins (e.g., Pb) in soils. This work focuses on the potential role of organic acids in protecting Changbai larch (Larix olgensis) seedlings from the stress of growing in nutrient deficient soil. The seedlings were planted in a nutrient rich or deficient soil (A1 horizon of a Haplic Cambisol without organ...

We examined patterns of nutrient heterogeneity in the mineral soil (0–15 cm depth) of 13 southern Appalachian forest stands in western North Carolina .60 yr after abandonment from pasture or timber harvest to investigate the long-term effects of land use on the spatial distribution and supply of soil resources. We measured soil carbon (C), nitrogen (N), acid-extractable phosphorus (P), potassiu...

Effects of biodiversity on productivity are more likely to be expressed when there is greater potential for niche complementarity. In soil, chemically complex pools of nutrient resources should provide more opportunities for niche complementarity than chemically simple pools. Ectomycorrhizal (ECM) fungal genotypes can exhibit substantial variation in nutrient acquisition traits and are key comp...

Background: As the decomposition of lignocellulosic compounds is a rate-limiting stage in the nutrient mineralization from organic matters, elucidation of the changes in soil enzyme activity can provide insight into the nutrient dynamics and ecosystem functioning. The current study aimed to assess the effect of thinning intensities on soil conditions. Un-thinned control, 20 % thinning, and 30 %...

Agriculture in the humid tropics is mostly limited by low soil fertility and invasion of weeds. The nutrient retention capacity of most soils is low and applied mineral fertilizers are rapidly leached into subsoil. Small farmers can not afford continuous mineral fertilizer input to compensate for the losses. Hence the dominating agricultural praxis is shifting cultivation accompanied with slash...