Abbreviations: DAT, days after transplanting; SF, starter fertilizer. 1 Former Graduate Assistant. Current address: Univ. of Vermont Extension Service, Box 2430, Brattleboro, VT 05301. 2 Associate Professor. 3 Professor. 4 Graduate Assistant
environmental concerns and P restrictions, many fertilizer companies have reduced or eliminated P in synthetic turfgrass maintenance fertilizers; however, P is still present in organic and starter fertilizers. Starter fertilizers typically contain higher amounts
Monoammonium phosphate (MAP) is a popular starter fertilizer in Pacific Northwest tree fruit orchards; however, its use on soils contaminated with lead arsenate pesticide residues can enhance As solubility, thereby increasing As phytoavailability. `Fuji'/EMLA.26 apple trees (Malus ×domestica Borkh.) were planted in Mar. 1992 on a lead arsenate-contaminated Cashmont gravelly sandy loam soil (HCl-extractable soil As range: 60-222 mg·kg-1) using in-hole starter fertilizer application of either MAP or ammonium sulfate at equivalent N and anion rates. In ensuing years, all trees received identical applications of ammonium nitrate only. Relative trunk cross-sectional area was inversely related to soil As concentration in the year of planting but not in subsequent years, and was independent of starter fertilizer treatment. Leaf and fruit As were positively related to soil As in all years. Leaf As was initially higher in the MAP-treated trees; however, this effect diminished over time and disappeared by 1995. Fruit As was independent of starter fertilizer treatment, and was substantially lower than the tolerance established for As in fresh produce. The experimental results indicate that MAP starter fertilizer can increase soil As phytoavailability to apple trees grown under field conditions; however, the effects on tree growth and food safety are insignificant.
Monoammonium phosphate (MAP) is a popular starter fertilizer in Pacific Northwest tree fruit orchards; however, its use on soils contaminated with lead arsenate pesticide residues can enhance As solubility, thereby increasing As phytoavailability. `Fuji'/EMLA.26 apple trees (Malus ×domestica Borkh.) were planted in Mar. 1992 on a lead arsenate—contaminated Cashmont gravelly sandy loam soil (HCl-extractable soil As range: 60-222 mg·kg-1) using in-hole starter fertilizer application of either MAP or ammonium sulfate at equivalent N and anion rates. In ensuing years, all trees received identical applications of ammonium nitrate only. Relative trunk cross-sectional area was inversely related to soil As concentration in the year of planting but not in subsequent years, and was independent of starter fertilizer treatment. Leaf and fruit As were positively related to soil As in all years. Leaf As was initially higher in the MAP-treated trees; however, this effect diminished over time and disappeared by 1995. Fruit As was independent of starter fertilizer treatment, and was substantially lower than the tolerance established for As in fresh produce. The experimental results indicate that MAP starter fertilizer can increase soil As phytoavailability to apple trees grown under field conditions; however, the effects on tree growth and food safety are insignificant.
Abstract
Three glasshouse experiments were conducted in which “starter” N, P, and K fertilizers were incorporated either within or below gel used for fluid sowing pregerminated seed of ‘Avondefiance’ lettuce (Lactuca sativa L.) and ‘Derby Day’ cabbage (Brassica oleracea L. Capitata group). Addition of nutrients to the gel at salt concentrations between 384 and 1893 mg-ion/liter inhibited emergence of the pregerminated seeds. Additions to the gel at concentrations between 9 and 21 mg-ions/liter were too low to affect the growth of the plants. Nutrient solutions applied to the base of the furrow immediately prior to fluid drilling the seeds allowed higher concentrations of salts to be used without reducing emergence. Solutions that contained factorial combinations of 0.84 g/liter N, 1.86 g/liter P, and 2.34 g/liter K applied at the rate of 0.5 ml/cm of furrow increased lettuce dry matter production by up to 44% after 20 days growth, although there was no significant effect on the growth of cabbage. The increase in lettuce growth was mainly in response to P ‘starter’ fertilizer but the largest response was achieved with the N + P + K ‘starter’ treatment.
chip substrates could partly be the result of N immobilization. The objective of this research was to evaluate supplemental starter fertilizer rate in combination with WholeTree as an alternative growth substrate and substrate component for greenhouse
Abstract
An integrated tomato seedling system was developed by assembling components to regulate plant population, apply starter fertilizer, and promote seedling emergence. Plant population was regulated by the release of 4-7 seeds per clump at the desired spacing in the row. Starter fertilizer was sprayed on the seed as a 2-3-0, N-P-K (2-7-0 oxide form) solution at 500 ml per 30 m (1 pint per 100 ft) of row. An anticrustant was applied into the seed furrow and firmed by a press wheel with a concave surface. The system was adapted to several commercial seeders and enabled the establishment of dependable stands on soils with crusting tendencies.
.L. Wien, H.C. Turneti, A.D. 1993 Tomato response to starter fertilizer, polyethylene mulch, and level of soil phosphorus J. Amer. Soc. Hort. Sci. 118 212 216 Henry, A. Chaves, N.F. Kleinman, P.J.A. Lynch, J.P. 2010 Will nutrient-efficient genotypes mine
Field studies were conducted in 1994 and 1995 to evaluate the effects of in-furrow-placed (i.e., applied directly in the seed channel) starter fertilizer on the emergence, maturity, and yield response of early sweet corn. In both years, three starter fertilizer treatments were applied: APP, with N and P at 13 and 19 kg·ha-1, respectively (13N-19P kg·ha-1), either banded (5 cm below and 5 cm to the side of the seed) or placed in-furrow, and a control (no starter fertilizer). Additionally, in 1995, the rate of APP was increased to supply 26N-38P kg·ha-1 in combination with either band (5 × 5 cm) or in-furrow placement. Seedling emergence was delayed whenever starter fertilizer was applied with the seed; however, significant reductions (≈21%) in plant stand occurred only at the high rate of in-furrow placement. In both years, all starter treatments had a positive effect on seedling dry-matter production, and hastened silking. In-furrow application of 13N-19P kg·ha-1 increased marketable ear yields 34% in 1995, but had no effect in 1994. Lack of yield response to the high rate of in-furrow fertilizer in 1995 was primarily a function of reduced stand, as ear number and ear mass per plant, and average ear size were similar to those in the other starter treatments. Based on these results, in-furrow APP at 13N-19P kg·ha-1 appears to be an effective starter fertilization regime for early sweet corn, comparable in effect to banded 26N-38P kg·ha-1. However, high rates of in-furrow APP may reduce stands. Although significant yield response to in-furrow starter fertilizer may not always be realized, the increased early seedling growth may itself be a benefit, since fast-growing seedlings are more likely to be tolerant of adverse environmental conditions than are less vigorous plants. Chemical name used: ammonium polyphosphate (APP).
Field studies were conducted in 1994 and 1995 to evaluate the effects of in-furrow-placed (i.e., applied directly in the seed channel) starter fertilizer on the emergence, maturity, and yield response of early sweet corn. In both years, three starter fertilizer treatments were applied: APP, with N and P at 13 and 19 kg·ha-1, respectively (13N—19P kg·ha-1), either banded (5 cm below and 5 cm to the side of the seed) or placed in-furrow, and a control (no starter fertilizer). Additionally, in 1995, the rate of APP was increased to supply 26N—38P kg·ha-1 in combination with either band (5 × 5 cm) or in-furrow placement. Seedling emergence was delayed whenever starter fertilizer was applied with the seed; however, significant reductions (≈21%) in plant stand occurred only at the high rate of in-furrow placement. In both years, all starter treatments had a positive effect on seedling dry-matter production, and hastened silking. In-furrow application of 13N—19P kg·ha-1 increased marketable ear yields 34% in 1995, but had no effect in 1994. Lack of yield response to the high rate of in-furrow fertilizer in 1995 was primarily a function of reduced stand, as ear number and ear mass per plant, and average ear size were similar to those in the other starter treatments. Based on these results, in-furrow APP at 13N—19P kg·ha-1 appears to be an effective starter fertilization regime for early sweet corn, comparable in effect to banded 26N—38P kg·ha-1. However, high rates of in-furrow APP may reduce stands. Although significant yield response to in-furrow starter fertilizer may not always be realized, the increased early seedling growth may itself be a benefit, since fast-growing seedlings are more likely to be tolerant of adverse environmental conditions than are less vigorous plants. Chemical name used: ammonium polyphosphate (APP).