Soil phosphorus availability and uptake by mycorrhizal and non-mycorrhizal plants in an onion no-tillage system

Abstract

Onion is an important vegetable crop, predominantly grown under conventional tillage system management. Alternatively, the vegetable no-tillage system uses cover crops to form a residue layer, which improves soil physical, chemical, and biological attributes. Aiming to understand the interaction of mycorrhizal and non-mycorrhizal cover crops, phosphatase activity, and soil phosphorus availability and uptake by plants, a no-tillage vegetable production system experiment with onion was carried out in Ituporanga, Southern Brazil. The treatments were black oats (Avena strigosa); rye (Secale cereale); oilseed radish (Raphanus sativus); rye + oilseed radish; black oats + oilseed radish, and a control with spontaneous plants. Additionally, two plots, a conventional tillage system area and a forest, both adjacent to the experiment, were evaluated. We measured cover crop biomass, onion yield, acid phosphatase activity, and resin-extracted phosphorus in the soil, shoot and root phosphorus content, and root colonization in cover crops, spontaneous plants, and onions. The treatments with cover crops had the highest plant biomass in winter and onion yield. Available soil phosphorus and acid phosphatase activity were higher in no-tillage plots than in the conventional tillage system area. The presence of non-mycorrhizal oilseed radish was associated with decreased colonization of rye and onion roots by arbuscular mycorrhizal fungi. No-tillage areas with cover crops or spontaneous plants in winter accumulated more phosphorus than conventional tillage system areas. The conventional tillage system showed adverse effects on most soil attributes, as shown by a Principal Component Analysis.

Biogenic and Physicogenic Aggregates Under Different Crops With Black Oat in Nova Friburgo, Brazil

“…In natural systems with no addition of phosphorus, P availability is related to the cycling of organic P. In fertilized soils, most available phosphorus is buffered by labile inorganic fractions (NOVAIS; SMITH, 1999). Thus, considering the addition of P fertilizers in the BO-F area, the results may be related to inorganic and organic P accumulations with different binding energy levels (SANTOS et al, 2008). Means followed by the same letter in the columns are not different by the Bonferroni test (p<0.05).…”

“…According to Silva et al (2011), poultry litter is a good source of nutrients that can substitute chemical P fertilization when properly managed. The organic and inorganic soil phosphorus fractions can be a source or drain for the soil solution, depending on their mineralogical characteristics, environmental conditions, soil fertilization, and soil management (SANTOS et al, 2008). In natural systems with no addition of phosphorus, P availability is related to the cycling of organic P. In fertilized soils, most available phosphorus is buffered by labile inorganic fractions (NOVAIS; SMITH, 1999).…”

Effect of Double-cropping and Crop Rotation Systems on Onion Bulb Yield Compared with Mono-cropping System in the Southern Kyushu Region of Japan

“…4) to support mycorrhizal infection. Ventura et al (2021) conducted an onion with no-tillage cultivation system after the cultivation of mycorrhizal cover crops of black oats and rye. They reported that the root mycorrhizal colonization rate was higher after rye cover cropping than under oilseed radish (non-mycorrhizal plant) cover cropping.…”