Phosphorus saturation and mobilization in two typical Chinese greenhouse vegetable soils

Land Use Changes Impact Distribution of Phosphorus in Deep Soil Profile

“…Compared with an increase in TP, the magnitude of increase in both soluble and labile P indicates that land use changes have increased proportions of both soluble and labile P to TP. Our results were in line with findings of other studies elsewhere on conversion of arable crop land to greenhouse vegetable or kiwi orchard (Qin et al 2010;Yan et al 2013;Kalkhajeh et al 2016). Such results may be resulted from several factors including (1) the overuse of chemical fertilizers and organic manure (Ju et al 2007;Yan et al 2013); (2) low P use efficiency by the vegetable crops or fruit trees (Gao et al 2012); (3) changes in soil properties, such as soil acidification and the leaching losses of SIC, sequestration of soil organic carbon (Tables 1 and 2), which increased solubility and thus, the availability of P; and (4) higher DPS values than the threshold level for alkaline soils reported from 4 to 20% (Akinremi et al 2007;Wang et al 2012;Rashmi et al 2018), which reduce P fixation and increase P solubility (Nair et al 2004).…”

“…In our tested soils, land use change from arable crop to greenhouse vegetable significantly increased soil P accumulation at surface layer, such as TP by more than 130%, Pi by 80%, and Po by 480%. Similar increases in TP have been reported elsewhere for such land use change (Darilek et al 2010;Yan et al 2016;Kalkhajeh et al 2016). This can be attributed to continuous and high inputs of phosphatic fertilizer and organic manure (Ju et al 2007;Yan et al 2013).…”

“…Phosphorus is a key nutrient requiring more attention on its accumulation and translocation in soil in response to land use changes. Compared with cereal crops, vegetables have different nutrient requirements with a higher P uptake (Yan et al 2013), and growers are more willing to apply larger quantities of animal manure and mineral fertilizers, to increase their productivity (Kalkhajeh et al 2016). Previously, many studies have reported that high inputs of phosphatic fertilizer and animal manure significantly augmented soil P accumulation as inorganic and/or organic-P forms at top soil layers.…”

Closing the Loop on Phosphorus Loss from Intensive Agricultural Soil: A Microbial Immobilization Solution?

“…This has greatly increased the P content of soil in various intensive agricultural systems (including cereals, vegetables, and fruit orchard), many of which now contain sufficient P to potentially supply P for adequate yields in these crops for several years (Li et al, 2011 ; Tóth et al, 2014 ). For example, the soil available P in some cereal crop, vegetable and orchard systems in China have arrived at 24.7, 181, and 43.1 mg kg −1 , respectively (Lu, 2009 ; Li et al, 2011 ; Kalkhajeh et al, 2017 ). Over-application of P fertilizer is in itself wasteful, but the transport of excessive P from soil solution to the waterbodies by surface runoff and leaching causes various environmental problems, including eutrophication of lakes, rivers and near coastal zones, pollution of ground water aquifers, algal blooms, and the loss of terrestrial and aquatic biodiversity (Chen et al, 2008 ; Schoumans et al, 2014 ; Smith et al, 2015 ).…”

OsPHT1;3 Mediates Uptake, Translocation, and Remobilization of Phosphate under Extremely Low Phosphate Regimes

“…The genetic and functional redundancy between PHT1 genes prevents/compromises the analysis of their specific roles, and the evidence of a phloem-localized PHT1 member in rice is lacking. In addition, plants need to acquire soluble Pi from environment with fluctuating Pi levels, ranging approximately from 0.3 mm to 3 mM (in natural ecosystems; Bieleski, 1973;Wang et al, 2012) to 30 mM to 300 mM (in intensively fertilized farmland; Kalkhajeh et al, 2017), yet no detailed analysis has been conducted for the activity of reported PTs at a wider range of Pi levels. This current state of the field led us to study other rice PHT1 members that remain uncharacterized.…”