The effects of humic acid application upon the phosphorus uptake of the tomato plant (Lycopersicum esculentum L.)

Abstract

Humic acid can transform mineral nutrients into available forms for the plants. High lime content, low organic matter content, high pH, low moisture content and insufficient profile characteristics all higher plant phosphorus uptakes and consequently regress plant growth and development. The present research was conducted to investigate the effects of humic acid treatments (H.A.) (0, 60, 120 mg/kg) on phosphorus use efficiency (PUE) (0, 50, 100 mg/kg P) of grape and pole tomato (Lycopersicum esculentum L.) varieties. Pot experiments were carried out in a glasshouse in randomized block design with three replications. As basic fertilization, 250 mg/kg N and 200 mg/kg K was applied to the pots. Plants were harvested when they had their 5 th raceme. Dry matter yields, N, P and K contents were analyzed. Dry matter yields increased with humic acid and phosphorus treatments. Phosphorus contents also increased with increasing phosphorus doses. While humic acid and phosphorus treatments affected the potassium contents, Ca contents increased through only the humic acid application.

The possible use of scarce soluble materials as a source of phosphorus in Vicia faba L. grown in calcareous soils

“…Regarding the combinations between organic substances and chelating agents, the treatment of HA+ citric acid was superior in giving high extractable amount of P in soil, followed by HA+ EDTA in most physiological stages of growing bean plants, with significant differences in the presence of added bacteria. Humic acid plays a vital role in increasing P availability in soil (Doran et al, 2003;Sahin et al, 2014), plus its considerable content of P (Table 1a). Citric acid, in addition to decrease soil pH, it makes complexes with Ca forming calcium citrate and releasing P in soluble form in the soil (Drouillon & Merckx, 2003).…”

“…Regarding the interaction between solubilizing agents, the treatment of HA+ EDTA, followed by that plus citric acid gave the highest concentration of P in plant leaves, with significant difference as compared to the other treatments. Sahin et al (2014) found that humic substances in interaction with P in the soil could decrease the P-fixation and increase the P-uptake by plants.…”