Many arable lands have accumulated large reserves of residual phosphorus (P) and a relatively large proportion of soil P is less available for uptake by plants. Root released organic anions are widely documented as a key physiological strategy to enhance P availability, while limited information has been generated on the contribution of rhizosphere organic anions to P utilization by crops grown...

1.1 Iron deficiency – The problem Iron (Fe) is an essential micronutrient for plants, humans and other animals. An adequate uptake of Fe is needed to ensure proper growth and development, as well as good health of organisms (Marschner, 1995; Vasconcelos and Grusak, 2007). When provided with insufficient quantities of Fe, organisms will suffer from Fe deficiency symptoms. Fe deficiency is a worl...

Sodium salicylate (1,000 mug/ml) was delivered through a drip irrigation system to agricultural field soils planted to tomato and infested with Pseudomonas putida PpG7, the host of the salicylate catabolic plasmid NAH7. In nonfumigated soils infested with approximately 10 CFU of PpG7 per g in the top 30 cm, population densities were increased up to 112-fold within 14 days of the initial applica...

Irrational phosphorus (P) nutrient management practices often fail to match of P fertilizer type, soil transformation and crop demand, lead increased accumulation legacy P, reduced PUE, pollution, affecting production. A pot experiment incorporating types (SSP, simple superphosphate; CMP, calcium magnesium phosphate; DAP, diammonium TSP, triple APP, ammonium polyphosphate; CK, no application) e...

The bacterial communities of 1- to 6-year ginseng rhizosphere soils were characterized by culture-independent approaches, random amplified polymorphic DNA (RAPD), and amplified ribosomal DNA restriction analysis (ARDRA). Culture-dependent method (Biolog) was used to investigate the metabolic function variance of microbe living in rhizosphere soil. Results showed that significant genetic and met...

Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorpt...

Management strategies that minimize P transfer from agricultural land to water bodies are based on relationships between P concentrations in soil and runoff. This study evaluated such relationships for surface runoff generated by simulated sprinkler irrigation onto calcareous arable soils of the semiarid western United States. Irrigation was applied at 70 mm h(-1) to plots on four soils contain...

zinc (zn) availability and mobility in soils is controlled by its interaction with the soil matrix and amendments. contradicting evidence has been reported for factors influencing zn behavior in soils. the aim of this study was to investigate the zn sorption in selected acid, calcareous and gypsiferous soils with different background electrolytes (na+, k+ and h2po4, no3 and cl backgrounds). iso...

The differences in rhizosphere nitrification activities between high- and low- fertility soils appear to be related to differences in dissolved oxygen concentrations in the soil, implying a relationship to differences in the radial oxygen loss (ROL) of rice roots in these soils. A miniaturised Clark-type oxygen microelectrode system was used to determine rice root ROL and the rhizosphere oxygen...