Resposta do sorgo sacarino (Sorghum bicolor (L.) Moench) ao emprego de fontes e doses de fósforo em condições de casa de vegetação: I. Latossolo vermelho escuro

Lima, E. F.; Malavolta, E.

doi:10.1590/s0071-12761982000200011

Cited by 1 publication

(1 citation statement)

References 3 publications

(3 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The beneficial effect of raising pH through liming is sometimes observed even when rock phosphate is the source of P2O5. LIMA & MALAVOLTA (1982) suggest that this effect is indirect due to better root invironment created by the limestone which helps the plant to absorb more phosphorus, thereby counter acting the influence of both high pH and high Ca + 2concentration on the solubility of the fertilizer.…”

Section: Limingmentioning

confidence: 99%

Increasing the efficiency of utilization of soil and fertilizer phosphorus in the subtropical and tropical agricultural systems C

Malavolta

Neptune

1983

An. Esc. Super. Agric. Luiz de Queiroz

Self Cite

View full text Add to dashboard Cite

As a rule, soils of the subtropical and tropical regions, in which rainfall is not limiting, are acidic, and low in phosphorus, and, to a less extent, in other macro and micronutrients as well, such a sulfur, boron and zinc. The establishment of a permanent agricultural prac. tice therefore, demands relatively high usage of liming and phosphatic fertilization, to begin with. Several approaches, not mutually exclusive, could be used in order to increase the efficiency of utilization of soil and fertilizer phosphorus so that, goal of diminishing costs of production is reached. The use of liming materials bringing up pH to 6.0-6.5 causes the conversion of iron and aluminum phosphates to more available calcium phosphates; on the other hand, by raising calcium saturation in the exchange complex, it improves the development and operation if the root system which allows c or a higher utilization of all soil nutrients, including phosphorus, and helps of stand water deficits which may occur. The role of mycorrhizal fungi should be considered as a way of increasing soil and fertilizer P utilization, as well as the limitations thereof. Screening of and breeding for varieties with higher efficiency of uptake and utilization of soil and fertilizer phosphorus leads to a reduction in cost of inputs and to higher benefit/cost ratios. Corrective fertilization using ground rock phosphate helps to saturate the fixation power of the soil thereby reducing, as a consequence, the need for phosphorus in the maintenance fertilization. Maintenance fertilization, in which soluble phos-phatic sources are used, could be improved by several means whose performance has been proved: limimg, granula tion, placement, use of magnesium salts. Last, cost of phosphate fertilization could be further reduced, without impairing yields, through impairing yields, through changes in technology designed to obtain products better adapted to local conditions and to the availability or raw materials and energy sources.

show abstract

Section: Limingmentioning

confidence: 99%