Starter Fertilizer Application Research Articles

The Effects of Nitrogen Starter Fertilizer and Plant Density on Yield, Yield Components and Oil and Protein Content of Soybean (Glycine max L. Merr)

Effects of nitrogen starter fertilizer and plant density on yield and oil and protein content of soybean (Glycine max L. Merr) are not well understood, because nitrogen starter fertilizer and plant density has been tested separately. Two years field experiment was conducted to evaluate effects of these factors on yield, yield components, oil and protein content in 2006 and 2007 in Kermanshah, Iran. The experiment was conducted on soybean (var. Williams) as a split-plot based on randomized complete blocks design with three replications. Nitrogen starter fertilizer treatments were arranged in three rates (0, 40, 80 kg ha(-1)) as main plots and plant density as sub plots arranged with three levels (15, 30, 45 plant m(-2)). Based on similarity treatments and experimental designs, the results of analysis of combined variance and mean comparisons showed significant (528.4 kg ha(-1) yield increase as density increased from 30 to 45 plant m(-2) and nitrogen starter fertilizer increased from 0 to 40 kg ha(-1) in two years. Analysis of correlation showed a positive significant correlation between yield and number of seed per plant (r = 0.724), number of pods and yield (r = 0.463), thousand seed weight and yield (r = 0.437). A linear regression was found between yield and number of seed per plant, number of pods and thousand seed weight (yield = 37.58 + 0.73x1-0.14x2 + 0.7x3; r2 = 0.56); p < 0.01). Seed protein was unaffected by plant densities, but nitrogen application changed it. Dissimilarly, oil content has a diverse respond to treatments. This experiment showed density of 45 plant m(-2) and application of nitrogen starter fertilizer 40 kg ha(-1) are optimum and increase grain yield under condition of our experiment. We suggest to conduct some experiments for understanding of linear relationship for number of pod for understanding of linear relationship for number of pod for levels of nitrogen starter and quadratic relationship for number of seed for levels of density.

Antecipação da adubação de semeadura do milho em dois sistemas de manejo do solo

Cada sistema de manejo do solo é trabalhado de maneira própria, alterando de forma diferenciada suas propriedades químicas, físicas e biológicas, podendo requerer modificações nas recomendações e no manejo da adubação. Com a finalidade de avaliar o desempenho de três cultivares de milho em relação à adubação realizada em pré-semeadura, comparada à adubação na semeadura, em dois sistemas de manejo do solo, foi realizado este estudo. O experimento foi conduzido na Faculdade de Ciências Agronômicas da UNESP, campus de Botucatu-SP, no período de novembro de 2003 a maio de 2004, em Nitossolo Vermelho distroférrico. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas subsubdivididas e quatro repetições. As parcelas foram constituídas pelos sistemas de manejo do solo (plantio direto e preparo reduzido com escarificação); as subparcelas, pelas épocas de adubação (adubação de pré-semeadura na superfície do solo, realizada 22 dias antes da semeadura do milho, e adubação feita junto com a semeadura do milho, sendo os fertilizantes incorporados ao solo); e as subsubparcelas, pelos cultivares de milho (DKB 333B, CO 32 e AL Bandeirante), totalizando 12 tratamentos. Os dados de produtividade, componentes de produção e teores de N, P e K no tecido foliar foram submetidos à análise de variância e às análises multivariadas de agrupamentos e de componentes principais. Os sistemas de manejo do solo não influíram no desempenho da cultura do milho, tampouco as épocas de adubação. As diferenças observadas nos componentes de produção e no desempenho da cultura do milho foram decorrentes, principalmente, da divergência genética dos cultivares de milho.

Starter Fertilizer and Row Cleaning Did Not Affect Yield of Early‐Planted, No‐Till Grain Sorghum

Cool soil temperatures in no-till production systems often slow early grain sorghum [Sorghum bicolor (L.) Moench] plant growth. This inhibitory effect may be reduced through use of starter fertilizer, nitrogen band-applied over the crop row, or removal of crop residues from the row before or at planting time to increase soil temperature. Six trials were conducted in 2004 and 2005 in eastern Nebraska with early-planted grain sorghum under continuous no-till conditions. Soil organic matter was 30 mg/kg or more and Bray-P1 ranged from 19 to 46 mg/kg in the top 5 cm of soil and from 6 to 11 mg/kg for the 5- to 20-cm depth. Application of N at 30 kg/ha in a band over the row at planting time, in-furrow application of starter fertilizer containing N+P or N+P+S, and row cleaning before or at planting all resulted in earlier flowering of sorghum. Grain water content was slightly reduced with row cleaning. However, none of these practices individually or in combination affected kernel size, panicle number or grain yield for early-planted grain sorghum grown in no-till conditions.

Hybrid and Planting Date Effects on Corn Response to Starter Fertilizer

Previous research has identified several factors that may influence corn response to starter fertilizer including hybrid genetics and planting date. However research examining the influences of these management factors on corn response to starter fertilizer has produced inconsistent results. The objective of this experiment was to determine if hybrid maturity and planting date affect corn yield responses to starter fertilizer. The experiment was conducted near Columbia, MO in 2000 and 2001 and consisted of eight hybrids with and without starter fertilizer. Hybrids were selected for a range in maturity. Starter fertilizer was placed 2 inches to the side and 2 inches below the seed at a rate of 30 lb of N per acre and 30 lb of P2O5 per acre. Starter fertilizer increased plant height for four of the five planting date-year combinations and reduced the number of days from planting to midsilk for all five combinations. The magnitude of the changes in plant height and number of days from planting to midsilk due to starter fertilizer application were greater for April planting dates than for May planting dates. Starter fertilizer increased corn grain yield in two of the five planting date-year combinations. Planting date had no effect on the magnitude of the yield response from starter fertilizer. Hybrid maturity affected plant height and days to midsilk responses to starter fertilizer for several planting dates. In instances when hybrid maturity affected the response to starter fertilizer, later-maturing hybrids responded more than early maturing hybrids. There was no effect of hybrid maturity on yield response to starter fertilizer.

Starter fertilizer to spring barley and spring wheat in south-east Norway: Effects on growth and nutrient uptake

Field experiments were carried out on three representative soils, to evaluate the effect of various starter fertilizers, together with different rates of band placed phosphorus (P), on nutrient uptake and yield of spring barley (Hordeum vulgare L.) and spring wheat (Triticum aestivum L.). The starter fertilizers were placed in the immediate vicinity of the seed, while the band placed P was placed at about 5 cm below the seeds and spaced at 25 cm between alternate seed rows. As starter fertilizer, monoammonium phosphate (MAP), calcium nitrate (CAN), ammonium nitrate (AN) and triple superphosphate (P20) were compared. In both species, effects of starter fertilizer on P uptake were most marked early in the growing season. At GS 13 application of 20 kg P ha−1 as MAP increased the P uptake by 50% in barley and by 35% in wheat, compared to no seed-placed nutrients. For grain, the increase in P content was 8% for both species. The higher P uptake at GS 13 was supported by observations of higher plant vigour in the treatments with either P20 or MAP as starter fertilizer. The use of N only as starter fertilizer did not increase the vigour of the plants. Band placement of P also gave more vigorous plants in spring barley. The grain yield increased on the silty clay loam and on the silt soil when starter fertilizer was applied, especially with the use of MAP. Smaller and non-significant yield differences were found when starter fertilizer was used on the loam soil. No delay or reduction of emergence was observed with starter fertilizer. Therefore, on soils where root growth or nutrient uptake becomes limited during the first weeks after sowing, application of starter fertilizer is recommended in Norway for both spring barley and spring wheat. Crops grown on silty soils seem to have an especially high demand for easily available P given as starter fertilizer.

Enhancing Corn Production Through the Use of Starter Fertilizer in the Northern Great Plains

The northern portion of the Great Plains has environmental conditions that require unique management practices to ensure optimum corn (Zea mays L.) yield and quality. The objective was to investigate the effect of starter fertilizer on corn yield and quality under different soil management. A field experiment was established within a 2‐year corn/soybean [Glycine max (L.) Merrill] rotation. Whole‐plot treatments were tillage with split‐plot treatments of starter fertilizer. Starter fertilizer treatments consisted of two nitrogen (N) sources, each at four rates, all contained phosphorus (P) and potassium (K). An additional treatment of no starter fertilizer was also incorporated into the experiment. There was a significant increase in yield with application of starter‐N for all years except 2002. The most dramatic yield increase was obtained with the comparison between the no starter (no N, P, or K) treatment and the P and K treatment (no N+P and K). Starter fertilizer with only P and K also increased yield, oil production, and N removal in all years compared with no starter fertilizer treatment. Application of starter fertilizer can have a significant positive impact on yield and quality of corn grown in the northern Great Plains. Mention of trade name or commercial products in this publication is solely for the purpose for providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

Phosphate Starter Fertilizer Temporarily Enhances Soil Arsenic Uptake by Apple Trees Grown under Field Conditions

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.

Phosphate Starter Fertilizer Temporarily Enhances Soil Arsenic Uptake by Apple Trees Grown under Field Conditions

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.

Starter fertilizer effects on grain sorghum hybrids grown on a soil high in residual phosphorus in a no‐tillage environment

Conservation tillage crop production systems have become common in the central Great Plains because they reduce soil erosion and increase water‐use efficiency. The high residue levels associated with no‐tillage systems can cause soils to be cool and wet which can reduce nutrient uptake and growth of crops. Starter fertilizer applications have been effective in improving nutrient uptake even on soils high in available nutrient elements. Resent research indicates that corn (Zea mays L.) hybrids differ in their responses to starter fertilizer. No information is currently available concerning grain sorghum [Sorghum bicolor (L.) Moench] hybrid response to starter fertilizer. The objective of this study was to evaluate grain sorghum hybrid responses to starter fertilizer in a no‐tillage environment on a soil high in available phosphorus (P). This field experiment was conducted from 1995 to 1997 at the North Central Kansas Experiment Field, located near Belleville, on a Crete silt loam soil (fine, montmorillonitic, mesic, Pachic Arguistoll). Treatments consisted of 12 grain sorghum hybrids and two starter fertilizer treatments. Fertilizer treatments were starter fertilizer [34 kg nitrogen (N) and 34 kg P2O5 ha‐1] or no starter fertilizer. Starter fertilizer was applied 5 cm to the side and 5 cm below the seed at planting. Immediately after planting, N was balanced on all plots to give a total of 168 kg N ha‐1. In all three years of the experiment, grain yield, total P uptake (grain plus stover), grain moisture content at harvest, and days to mid‐bloom were affected by a hybrid x starter fertilizer interaction. Starter fertilizer consistently increased yields, reduced harvest grain moisture, improved total P uptake, and reduced the number of days needed from emergence to mid‐bloom of Pioneer 8505, Pioneer 8522Y, Pioneer 8310, Dekalb 40Y, Dekalb 48, Dekalb 51, Dekalb 55, and Northrup King 524, buthadno effect on Pioneer 8699, Dekalb 39Y, Northrup King 383Y, and Northrup King 735. When averaged over the three years, starter fertilizer increased grain yield of responding hybrids (hybrids in which the 3‐year average grain yield was significantly increased by the application of starter fertilizer) by 920 kg ha‐1. In responding hybrids, starter fertilizer reduced grain moisture at harvest by 54 g kg1 and also shortened the period from emergence to mid‐bloom by five days. Starter fertilizer increased V6 stage aboveground dry matter production and N and P uptake of all hybrids tested. Results of this work show that in high residue production systems even on soils high in available P, starter fertilizer can consistently increase yield of some hybrids, whereas other hybrids are not affected.

Phosphate Starter Fertilizer Temporarily Enhances Soil Arsenic Uptake by Apple Trees Grown under Field Conditions

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.

Cotton response to placement and rate of starter fertilizer

Application of starter fertilizer at‐planting is a convenient method of applying phosphorus (P) and pre‐plant nitrogen (N) to cotton (Gossypium hirsutum L.). In addition, the placement of starter fertilizer in‐furrow requires no extra tanks or pumps, and can be tank mixed with at‐planting insecticides, fungicides, or plant growth regulators. Over a four‐year period, tests were initiated to determine the effect of 10–34–0 starter fertilizer applied in‐furrow and in a 5 cm to the side and 5 cm below the seed placement (5 cm x 5 cm). Lint yields were measured all four years. Stand counts, Chambers’ skip index, and plant heights were measured the final year. Placement of starter fertilizer in‐furrow was shown to decrease yields compared to a 5 cm x 5 cm placement and a check two out of four years. Plant stands, skip indexes and plant heights were adversely affected by an in‐furrow placement as well. A 5 cm x 5 cm placement did not significantly differ in terms of yield in any year from the check. Plant stands and skip indexes were not affected, but plant height was increased over the check with one rate of starter placed 5 cm x 5 cm. Our results suggest that in‐furrow placement of starter fertilizer has the potential to negatively affect seedling growth and decrease yields. A 5 cm x 5 cm placement of starter fertilizer, while it may not increase yields, does not incur these risks and is a safe, convenient and inexpensive method of applying P or pre‐plant N.

Effect of planting date, starter fertilizer, and fungicide interaction on cotton

It is widely believed that starter fertilizer applications and fungicide treatments, either separate or in combination, can lead to increased plant stands and yields in cool, wet growing seasons. Over a three year period, tests were conducted to evaluate the efficacy of these treatments on cotton (Gossypium hirsutum L.). Two methods of starter application and two fungicide treatments were evaluated over two planting dates. Seedling stand counts and lint yield were measured. Our results show that on a North Carolina coastal plain soil there were no interactions between the treatments. A placement of starter fertilizer 5 cm to the side and 5 cm below the seed showed to have more consistent results in increasing plant stand and yield over a banded application. Fungicide treatments were not effective in increasing plant stands and increased yield in only one year over the untreated check. Yield was positively influenced by earlier planting dates and stand was found to increase in one year with an earlier planting date. Our results suggest that starter fertilizer applications can increase yield and plant stand in good years, but there is no interaction between starter fertilizers, fungicide treatments, and planting date on well‐drained coastal plain soils.

Corn Hybrid Response to Starter Fertilizer in a No-Tillage, Dryland Environment

A dryland corn (Zea mays L) production system that has gained popularity in Kansas involves planting as early in the spring as possible so that pollination occurs under more favorable moisture and temperature conditions. Cool soils that occur with early planting in high-residue production systems can reduce nutrient uptake. Starter fertilizer applications have been effective in enhancing nutrient uptake even on soils high in available nutrients. Corn hybrids may differ in their response to starter fertilizer. The objective of this study was to evaluate corn hybrid response to starter fertilizer in a notillage, dryland environment. This field experiment was conducted from 1993 to 1995 at the North Central Kansas Experiment Field, located near Belleville, on a Crete silt loam soil (fine, montmorillonitic, mesic Pachic Arguistoll). Treatments consisted of five corn hybrids and two starter fertilizer treatments. Fertilizer treatments were starter fertilizer (30 lb N and 30 lb P 2 O 5 /acre) or no starter fertilizer. Starter fertilizer was applied 2 in. to the side of and 2 in. below the seed at planting. In all 3 yr of the experiment, grain yield, maturity, and total P uptake (grain plus stover at maturity) were affected by a hybrid x starter fertilizer interaction. Starter fertilizer consistently increased yields, reduced the number of thermal units needed from emergence to midsilk, and increased total P uptake of Pioneer 3346, Dekalb 636, and Dekalb 591, but had no effect on ICI 8599 and Pioneer 3563. When averaged over the 3 yr of the experiment, starter fertilizer increased grain yield of responding hybrids (hybrids in which the 3-yr average yield was increased by the use of starter fertilizer) by 13 bu/acre. Starter fertilizer increased V6 stage above ground dry matter production and N and P uptake of all hybrids evaluated. Ear leaf N and P concentrations also were increased by starter fertilizer, regardless of hybrid. Results of this work show that starter fertilizer can increase grain yield and be feasible for some hybrids, whereas yields of other hybrids are not affected.

Agronomic potential of some agricultural wastes as surface mulches in hot pepper and tomato production in the Central Region of Ghana

Studies were carried out at the Teaching and Research Farm of the University of Cape Coast, in the minor seasons of 1992 and 1993, to assess the agronomic potential of some common agricultural wastes as surface mulches in terms of weed control, nematode population in soil, root-knot incidence and growth and yield of pepper (Capsicum frutescens L.) and tomato (Lycopersicon esculentum Mill.). There were six mulch treatments, namely grass, sawdust, baggasse, palm fruit fibre, chopped palm bunch, corn cob and a no-mulch control arranged in a randomized complete block design with four replications in the pepper trial. Corn cob was not included in the tomato trial which was also replicated four times. Mulching promoted early flowering in both pepper and tomato probably through its reduction of soil surface temperature. Fresh weight of weeds was also significantly reduced by mulching. The degree was, however, related to type of mulch, with bagasse and chopped palm bunch as the best on account of the size and density of the aggregates and compactness of the cover. Even though mulching tended to increase population of nematodes in the soil with time, there was relatively fewer incidence of root-knots in mulched pepper and tomato than in no-mulching. With the exception of palm fruit fibre, mulching significantly increased yields of both crops with bagasse and sawdust being outstanding in this regard. Superiority of the two might derive from their capacity to soak up and conserve more moisture than the rest due to the absorbent nature of their aggregates. Analysis of the nutrient composition of the different mulching materials showed that apart from grass which contained a little more than 1 percent nitrogen, the rest were very low in nitrogen and phosphorus but high in carbon with C:N ratio of over 187:1; that would rather require application of starter fertilizer to compensate for the initial depression of nitrification. (Ghana Journal of Agricultural Science, 1997, 30(1): 45-52)

Starter Fertilizer and Planting Date Effects on Corn Rotated with Cotton

AbstractCorn (Zea mays L.) has become an important crop used in rotation with cotton (Gossypium hirsutum L.) in the mid‐South region of the USA, but there has been little research on cultural practices for corn in this cropping system. The objective of this study was to determine if starter fertilizer has beneficial effects on corn growth and grain yield at different planting dates. Starter fertilizer and planting date effects were evaluated for corn in field experiments on a Commerce silt loam (fine‐silty, mixed, nonacid, thermic Aeric Fluvaquent) for 3 yr (1991 through 1993). Six hybrids were evaluated with two starter fertilizer treatments at four planting dates. Starter treatments were (i) ammonium polyphosphate (11‐37‐0 N‐P‐K) applied in‐furrow and (ii) a control with no starter fertilizer. Planting dates were mid‐March, early April, mid‐April and late April or early May. Yield response to planting date was not consistent across years; in two of three years, however, planting later than early April decreased yield. The starter fertilizer increased grain yield in two of the three years. Yield response to starter fertilizer was not consistent across years, hybrids, or planting dates. The planting date × starter interaction for yield was significant in two of three years and the hybrid × starter interaction for yield was significant in one of three years. Starter fertilizer increased early‐season plant height by 2 to 36% and increased grain yield across planting dates from 0.5 to 1.4 Mg ha−1 in 1991 and 0.4 to 1.0 Mg ha−1 in 1993. There was no yield response to starter in 1992. Application of starter fertilizer, averaged across hybrids and years, reduced harvest grain moisture 5% and days to silking by 3 to 5 d. In this mid‐South study, in‐furrow N‐P starter fertilizer increased early‐season corn plant height and grain yield and decreased the number of days to silking of corn rotated with cotton.

Interaction of Manure and Nitrogen or Starter Fertilizer in Northern Corn Production

Nutrient availability of applied manure may be reduced under the cool early season climatic conditions found in the far northern corn (Zea mays L.)-growing environments. This study evaluated the effectiveness of combining applications of starter and N fertilizers with manure on improving corn growth and soil nutrient levels in northern Wisconsin from 1979 to 1981. Residual effects of treatments also were evaluated from 1982 to 1983. Main treatments of five rates of manure (0, 19, 33, 60, and 121 tons/acre on a wet weight basis) were arranged in a split-strip plot design with split plot treatments of four rates of N fertilizer (0, 40, 80, and 120 lb N/acre) and strip plot treatments of two starter fertilizer rates (0 and 150 lb/acre of 6-24-24). Although application of manure and N fertilizer consistently increased silage dry matter yields, application of starter fertilizer affected yields in only 1 of the 3 yr in which treatments were applied. Climatic conditions alone were not sufficient to explain crop response to starter fertilizer. No interactions between manure and starter fertilizer or manure and broadcast N fertilizer applications were observed. Research Question In northern regions of the Corn Belt, cool spring temperatures may affect early season nutrient availability from dairy manure applications. Possible management of this short-term nutrient need may require additional applications of N or starter fertilizers. This study was established to determine the seasonal and residual effects of combining applications of starter or N fertilizers with manure on corn silage and soil nutrient levels. Literature Summary Lower soil temperatures experienced in northern climates decrease rates of N mineralization from manure applications and reduce plant availability of other nutrients, such as P. Annual corn yield response to application of starter fertilizer is inconsistent in the northern corn-growing states, but often results in improved early season growth. Factors affecting crop response to starter fertilizer include soil type, tillage method, rate and composition of starter fertilizer, and planting date. Combined applications of broadcast N fertilizer and manure have resulted in higher corn yields by overcoming the relatively low initial N availability from manure and by the addition of other nutrients contained in manure. Study Description Corn hybrid Warwick SL207 (75 d relative maturity) was grown for each year from 1979 to 1983 at Ashland, WI. Treatments were combined or applied separately for the 1979 to 1981 seasons and residual treatment effects examined during the 1982 and 1983 seasons. Soil: Manistee sandy loam (sandy over clayey, clayey, mixed, frigid Al-fic Haplorthod) Treatments: 0, 19, 33, 60, and 121 tons/acre dairy manure 0, 40, 80, and 120 lb N/acre N fertilizer 0 and 150 lb/acre starter fertilizer (6-24-24) Treatment Design: Split-strip plot design in randomized complete blocks with four replications Weed control: Alachlor (2 qt/acre) and atrazine (2 lb/acre) Applied Questions Did the application of N or starter fertilizers in combination with manure increase corn silage yields? Combining N or starter fertilizers with manure did not consistently increase silage yields beyond yields obtained with each fertility source applied separately. Yield advantages of manure and N fertilizer applications were consistent from year to year (Fig. 1), although annual yield response to manure during years of application and subsequent residual cropping seasons was higher because of crop response to manure P and K and possibly to other effects of manure on soil physical and biological properties. Application of starter fertilizer raised yields in 1 of the 3 yr in which treatments were applied (Table 1). Variability in early and late season climatic conditions and differences in annual crop nutrient demand from variable plant populations may have been factors limiting corn response to starter fertilizer applications. Interpretation of the results is complicated by the accumulation of soil P and K and organic N after repeated manure applications to the same plot area. This accumulation possibly reduced crop response to starter applications and also had significant positive residual effects on subsequent crop yields. Recommendations The results of this study do not provide a clear resolution to the need for annual applications of starter fertilizer in combination with manure applications under northern climatic conditions. The application of N fertilizer may be advisable, however, when used in situations where low rates of manure (less than 33 tons/acre) have been applied or when minimal residual effects from previous manure applications are expected. Table 1. Effect of starter fertilizer on silage yield, 1979 to 1983. Years treatments applied Residual years Starter 1979 1980 1981 1982 1983 --------------------tons/acre-------------------- Without 3.4 4.2 3.4 1.9 3.3 With 3.3 4.1 3.8 1.8 3.4 LSD (0.05) NS† NS 0.3 NS NS † NS = not statistically significant. Figure 1Open in figure viewerPowerPoint Yield response to manure and N fertilizer applications for 1979 to 1981. Bars indicate LSD (0.10) for comparison of N fertilizer treatment means at each rate of manure application.

Corn Hybrid‐Starter Fertilizer Interaction for Yield and Lodging

The value of placing small amounts of soluble fertilizers in close proximity to the seed at corn (Zea mays L.) planting was debated in the early 1980s for corn grown in a high‐yield environment, but is becoming an accepted practice in the southeastern USA. The objective of this study was to evaluate yield and lodging of several corn hybrids to starter fertilizer application in a high‐yield environment. Starter and no‐starter were the two fertility treatments. Starter was applied as NH4‐polyphosphate (10‐15‐0) in a band on the soil surface at planting. Rainfall was measured, and irrigations scheduled with tensiometers. Starter fertilizer significantly increased grain yields compared to no‐starter. Hybrid ✕ year and hybrid ✕ starter treatment interactions were significant. Certain corn hybrids were identified as positive changers (Funks G4733, Asgrow RX777, Sunbelt 1880, Pioneer 3320, Jacques JX247, Jacques 8400, Northrup King PX9581, and Coker 8680) that consistently yielded more with starter than others identified either as nonchangers or as negativechangers. Percent lodging generally was greater with no starter fertilizer (year ✕ starter and hybrid ✕ starter interactions were nonsignificant). Hybrid ✕ year interactions for percent lodging were significant. Certain corn hybrids (Jacques JX247, DeKalb DK748, and Jacques 8400) consistently exhibited less lodging than the hybrid mean when fertilized with a starter. The management implication is that certain corn hybrids may be profitably fertilized with a starter fertilizer but others may not, since they either do not respond (nonchangers) or respond negatively to starter fertilizer.

In-row tillage methods for subsoil amendment and starter fertilizer application to conservation-tilled grain sorghum

Acid subsoils and tillage pans limit crop yields on sandy soils of the Southern Coastal Plain of the United States. Studies were conducted for 3 years on two soils with acid subsoils and tillage pans to determine the effect of starter fertilizer (22 kg N, 10 kg P ha −1 and fluid lime (1350 kg ha −1) placement with in-row tillage methods on growth and yield of grain sorghum ( Sorghum bicolor (L.) Moench) grown in a conservation-tillage system. Fertilizer and lime were applied in factorial combinations in the in-row subsoil channel, in a narrow (4-mm) slit 18 cm below the tillage pan (slit-tillage), or 7 cm to the side of the row incorporated 7 cm deep. Slit-tillage was as effective as subsoiling in two of the four tests where plant growth and grain yield responded to deep tillage. Of the other two tests where there was a response to deep tillage, slit-tillage resulted in a 6% decrease in grain yield compared to subsoiling in one test, and an 8% yield increase in the other. Starter fertilizer placement was not critical, but response to starter fertilizer occurred only when deep tillage, either in-row subsoiling or slit-tillage, was used in conjunction with the fertilizer. Starter fertilizer consistently increased early-season plant growth; however, yield response to starter fertilizer was highly dependent on rainfall. Starter fertilizer application increased yield in only one of five tests. There was no benefit from injecting lime.

The effects of soil temperature on the response of lettuce seedlings to starter fertilizer

A pot experiment is described which investigated the effects of placing starter fertilizer, 1 cm beneath the seeds, on growth and nutrient uptake in lettuce seedlings at two soil temperatures (10°C and 20°C). At both temperatures the presence of starter fertilizer increased nutrient concentrations within the plants. At 20°C there was no growth response to the starter treatments. However, at 10°C there was a large response to the application of starter fertilizer. The best treatment was a combination of NH4H2PO4 and KH2PO4 which increased plant dry weight by 64% at 19 days from sowing. Nutrient deficiency caused a significant increase in the root length/shoot weight ratio of the control plants at 10°C. The responses to the starter were shown to be determined by the balance between the demand for nutrients from the shoots and the supplying power of the roots.

Corn growth and yield responses to starter fertilizers in conservation-tillage systems

The purpose of this 3-year field study, which was conducted on a Norfolk sandy loam (Typic Paleudult), was to determine if initial growth and final yield of corn ( Zea mays L.) grown in conservation-tillage systems (chisel plow and strip tillage) could be improved by the application of starter fertilizer. Treatments consisted of six starter fertilizer combinations (0-0-0, 24-0-0, 0-26-0, 0-0-66, 24-26-0, 24-26-66 kg ha −1 of NPK, respectively). The initial soil pH was 6.0 and soil test P and K levels were high. Side-dress N (224 kg ha −1) was applied 6 weeks after planting. The corn was planted with an in-row subsoiler planting unit and the fertilizers were placed in the subsoil tracks. Plant heights 6 weeks after planting were greater with than without starters, but this difference was primarily due to N. Concentrations of N, P and K in the young plant tissue, regardless of tillage, were increased when these nutrients were included in the starter combinations. Nitrogen concentrations in the ear leaf were not affected by treatments. Leaf K was higher with than without K-containing starters each year, but leaf P was higher with than without P-containing starters in only 1 year. Grain yields were increased by the N-containing starter fertilizers each year. The yield increases were more closely related to differences in early-season plant growth than to differences in nutrient concentrations in plant and leaf tissue. In 2 years, the NPK combination resulted in highest yields, but in the other year, NP was adequate. Higher grain yields were obtained with the strip-tillage than chisel-plow system in 2 of the 3 years.