soil test recommendation tables based on field research data obtained in North Dakota, South Dakota, western Minnesota and the Canadian Prairie Provinces.
Potassium (K) is an essential nutrient for normal plant growth and development, which plays a particularly important role in fiber development. Potassium defi¬ciency results in decreased fiber quality and lowered yields. If K is limited during active fiber growth, there is a reduction in the turgor pressure of the fiber result¬ing in less cell elongation and shorter fibers at maturity.
Controlled-release sources of N and K were compared with soluble sources on young orange trees.The effects of these fertilizers on leaf mineral concentration, soil chemical analysis, and tree growth were evaluated for 3 years. Soluble fertilizers were generally more readily available but had shorter residual effects on leaves and soil than controlled-release fertilizers.
A field experiment with pineapple was carried in the state of São Paulo, Brazil, with the objective of investigating the effects of rates and sources of potassium fertilizer on plant growth and fruit yield. Plant growth and fruit yield were evaluated. Biomass accumulation of pineapple plants was impaired by chlorine added with potassium chloride.
A corn crop takes up nearly as much potassium (K) as it does nitrogen (N), yet management of each nutrient is entirely different. Whereas harvesting 125 bushels of corn grain per acre removes only 35 lbs of potash (K2O), harvesting 21 tons of silage per acre carries away 160 lbs of K2O; and the voracious appetite of a 5-ton per-acre alfalfa crop takes 230 lbs of K2O per acre from a field.
In India, pulses are grown mostly on marginal and sub-marginal lands without proper inputs. Many field experiments on various pulse crops show yield benefits from K application. Improved K supply also enhances biological nitrogen (N) fixation and protein content of pulse grains.
Fertigation is the application of soluble nutrients via the irrigation water; its use in vegetable production has increased with the introduction of polyethylene mulch and drip irrigation, and it is an efficient means to apply fertilizer to the root zone.
The relationships between blossom end rot (BER) of vegetable fruits and fertigation regimes are reviewed. Many fruit disorders are affected by nutrient deficiencies or unbalanced nutrition: BER, gold specks, green back, blotchy ripening, color spots, malformation, hollowness and fruit cracking.
Cotton production in India has stagnated at a level far below its potential - the main reason being unbalanced and low rates of fertilizers. A review of key research on improved potassium (K) management practices provides a clear picture of the potential yield and economic benefits available to farmers.
The soybean aphid has become the most important insect pest of soybeans in the North- east and Midwest regions of North America. It often damages soybean plants that are K-deficient more than those that are not.