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
Subhrajit K. Saha, Laurie E. Trenholm, and J. Bryan Unruh
Catherine S.M. Ku and David R. Hershey
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
A. Liptay and P. Sikkema
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.
Timothy K. Broschat
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.
T.K. Hartz and R.F. Smith
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
Laurie E. Trenholm and Jerry B. Sartain
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
James E. Altland and James C. Locke
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
Sueyde Fernandes de Oliveira Braghin, Simone C. Mello, Jéssika Angelotti-Mendonça, Keigo Minami, and Yuncong C. Li
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
Catherine S.M. Ku and David R. Hershey
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
Janet C. Cole and John M. Dole
These studies were conducted to determine the effect of 1) temperature on P leaching from a soilless medium amended with various P fertilizers, 2) water application volume on P leaching, and 3) various fertilizers on P leaching during production and growth of marigolds (Tagetes erecta L. `Hero Flame'). Increasing temperature linearly decreased leaching fraction; however, total P leached from the single (SSP) or triple (TSP) superphosphate-amended medium did not differ regardless of temperature. Despite a smaller leaching fraction at higher temperatures and no change in the total P leached, P was probably leached more readily at higher temperatures. More P was leached from the medium amended with uncoated monoammonium phosphate (UCP) than from the medium containing polymer-coated monoammonium phosphate (CTP) at all temperatures, and more P was leached from UCP-amended medium at lower temperatures than at higher temperatures. More P was leached from TSP- than from SSP-amended medium and from UCP- than from CTP-amended medium regardless of the water volume applied, but leachate P content increased linearly as water application volume increased for all fertilizers tested. Plant dry weights did not differ regardless of P source. Leachate electrical conductivity (EC) was lower with TSP than with SSP. Leachate EC was also lower with CTP than with UCP. A higher percentage of P from controlled release fertilizer was taken up by plants rather than being leached from the medium compared to P from uncoated fertilizers.