effects of different soil moisture regimes and p application on available and inorganic p forms were studied in four paddy soils, north of iran. a factorial experiment in a completely randomized design with two replications was performed in a laboratory study. factors of soil at four levels (two acid and two alkaline-calcareous soils), soil moisture contents at three different levels (air-dry, ...

In soil, bioavailable inorganic orthophosphate is found at low concentrations and thus limits biological growth. To overcome this phosphorus scarcity, plants and bacteria secrete numerous enzymes, namely acid and alkaline phosphatases, which cleave orthophosphate from various organic phosphorus substrates. Using profile hidden Markov modeling approaches, we investigated the abundance of various...

this study was carried out to investigate the effect of crown canopy of ziziphus spina-christi on seed bank characteristics (density and similarity with above ground flora) in two sites with saline-alkaline and alkaline soils. in each soil, forty plots were established, half in and half outside of z. spina-christi cover. in each plot, soil sampling was done from 0-5 and 5-10 cm depths. paired a...

Salt-alkali is the main threat to global crop production. The functioning of phosphorus (P) in alleviating damage to crops from saline-alkaline stress may be dependent on the variety of crop but there is little published research on the topic. This pot experiment was conducted to study if P has any effect on rice (Oryza sativa L.) yield, dry matter and P accumulation and translocation in salt-a...

-Plant roots and soil organisms increase phosphorus availability by releasing acid and alkaline phosphatase. Organic phosphorus compounds are hydrolysed into plant-available forms through the action of these enzymes. Phosphatase is of particular importance under conditions of low phosphorus availability which is commonly found in pinon-juniper soils. Acid and alkaline phosphatase activities (mg...

Anaerobic soil conditions resulting from flooding often enhance release of phosphorus (P) to overlying water. Enhanced P release is well documented for flooded acidic soils; however, there is little information for flooded alkaline soils. We examined the effect of flooding and anaerobic conditions on P mobilization using 12 alkaline soils from Manitoba that were either unamended or amended with...

Extracellular enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight hydrolytic enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferon...

Four types of soil (red, yellow, cinnamon, and paddy soil) from China were used to conduct experiments in pots to study the influence of humic acid (humic acid (HA) and fulvic acid (FA)) on the accumulation of lead (Pb) and cadmium (Cd) in tobacco leaves. In non-polluted soils, the tobacco leaf uptake of Cd was dramatically influenced by the total soil metal concentration and soil properties, w...

BACKGROUND AND AIMS High Al resistance of Rumex obtusifolius together with its ability to accumulate Al has never been studied in weakly acidic conditions (pH > 5.8) and is not sufficiently described in real soil conditions. The potential elucidation of the role of organic acids in plant can explain the Al tolerance mechanism. METHODS We established a pot experiment with R. obtusifolius plant...