leach through soils and contaminate groundwater if not properly applied, although other research has shown that properly applied fertilizer is assimilated by the grass ( Erickson et al., 2001 ; Snyder et al., 1984 ). Proper fertilizer management
Abbreviations: EC, electrical conductivity EC a , EC of the applied solution; EC e , EC of a saturated medium extract; ET, evapotranspiration; LF, leaching fraction; LR, leaching requirement; M a , mass of pot after irrigation when at container
Tomato (Lycopersicon esculentum Mill) seedlings given 0.3 to 0.4 L/tray per day of a mineral solution containing (in mg·L-1) 150N-47P-216K-64Ca-40Mg maintained optimal height at 10 to 13 cm for Ontario processing tomato transplants. Seedlings given greater fertigation volumes were too tall and spindly to use as transplants. Transplants given 0.2 L of water per tray per day were very short (6 cm) compared to those receiving 0.3 to 0.4 L. As fertigation volume was increased from 0.2 to 0.7 L, shoot N remained constant while root N increased. Shoots had about a 3-fold higher level of N, P, and K than the roots. Calcium and magnesium were similar in roots and shoots. Mineral leaching from the trays was 1% of the total volume applied for the 0.4-L and 4% for the 0.7-L treatment.
Release rates for 13 commercially available soluble and controlled-release K fertilizers were determined in sand columns at 21C. Potassium chloride, KMgSO4, and K2CO3 were leached completely from the columns within 3 or 4 weeks. Osmocote 0N-0P-38.3K, Multicote 9N-0P-26.7K, the two S-coated K2SO4 products, and Nutricote 2N-0P-30.8K Ty 180 all had similar release curves, with fairly rapid release during the first 20 to 24 weeks, slower release for the next 10 to 12 weeks, and virtually no K release thereafter.
maximized when in-season N leaching potential is significant. Many studies documenting CRF benefits were conducted on sandy soils and in environments receiving significant in-season precipitation; CRF research on potato production in Florida ( Hutchinson
assess BMP recommendations, FDEP-funded research is currently underway to quantify nutrient leaching in three locations statewide and to verify the existing BMPs. Results from this research may also assist in providing recommendations for some of the
thus far seems to indicate similar potential benefits in soilless substrates including additions of some nutrients, reduction in leaching of nitrates and phosphates, beneficial shifts in microbial populations, and improved physical properties. Despite
Leaching of salt from container media was investigated by means of the miscible displacement theory for 6 peat-perlite-glass bead combinations plus 4 other mixes. Columns were salinized with 15 meq 1−1 each CaCl2 and NaCl, then allowed to equilibrate. Electrical conductivity of the effluent was recorded as columns were leached, using 1 cm constant water head, with solutions of 1, 4, or 7 meq 1−1 each of CaCl2 and NaCl. The replacement efficiency of the soil solution by the leaching solution increased as glass bead content increased. Replacement efficiency of the soil solution had high correlation with mixture physical properties. No relationship to particle size distribution could be ascertained. Leaching solution concentration did not influence replacement efficiency and, generally, after 1 to 1.5 container capacities of effluent, removal of the original soil solution decreased substantially.
quality, increasing the fertilizer use efficiency and preventing losses of nutrients, especially nitrogen (N) by leaching or denitrification ( Fageria and Baligar, 2005 ). CRFs are designed to release nutrients into the grown medium at a rate more closely
Abbreviations: EC, electrical conductivity; EC a , EC of the applied solution; EC e , EC of a saturated medium extract; ET, evapotranspiration; LF, leaching fraction; LI, leaching intensity; LR, leaching requirement; M a , mass of pot after