› › Evaluating Organic Nitrogen Fertilizer Sources Rates And Timing In Northern Highbush Blueberry Grown In High Ph Soils Of Eastern Washington

Evaluating Organic Nitrogen Fertilizer Sources, Rates, and Timing in Northern Highbush Blueberry Grown in High PH Soils of Eastern Washington

Author : Amit Bhasin

Publisher :

Page : pages

File Size : 38,35 MB

Release : 2020

Category : Blueberries

ISBN :

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Northern highbush blueberry (Vaccinium corymbosum L.) prefers acidic soils with high organic matter while growers in eastern Washington utilize amended soils with high native pH and low organic matter content. These edaphic conditions can influence nutrient cycling and plant available forms, which can affect plant growth, development, and fruit production. Furthermore, in eastern Washington, the semi-arid climate provides extended growing conditions after harvest for early-fruiting cultivars. This may require growers to continue nitrogen (N) fertilizer applications postharvest to support vegetative growth that could benefit fruit production in the following years. However, postharvest N applications could be detrimental as it may stimulate excessive vegetative growth, reduce floral bud set, and increase the risk of winter injury. The overall objective of this study was to provide baseline data to guide future nutrient recommendations for eastern Washington organic blueberry growers with an emphasis on N. Two experiments were conducted, and the sub-objectives were: 1) Determine optimal organic N fertilizer sources and rates and 2) Evaluate the impacts of postharvest N applications on fruit bud set and cold hardiness in early-fruiting ‘Duke’ blueberry. In experiment one, treatments included: 1) Blood meal; 2) TRUE 402 fish emulsion; 3) WISErganic; and 4) Combination (40% blood meal and 60% WISErganic). Fertilizer rate was split within source at 57, 112, and 168 kg·ha-1 N. The postharvest N experiment included four treatments varying in timing of N application. No yield and vegetative growth differences were observed across the fertilizer source and rate experiment during the two years in which this study was conducted. Leaf N concentrations increased with higher rates of N application. For postharvest N experiment, fruit bud set was similar across treatments and susceptibility of buds to cold was low across the treatments. While not statistically different, average plant yield in two years tended to increase with later fertilizer application dates. The lack of treatment differences can be attributed to plant age and the short duration of the experiment since blueberry plants can store nutrients in their tissues. Further years of data collection are required to better understand how these perennial plants are responding to these treatments.



Nitrogen Supply from Soil Organic Matter

Author : Cheyenne Sloan

Publisher :

Page : 71 pages

File Size : 37,92 MB

Release : 2021

Category : Humus

ISBN :

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Northern highbush blueberry (Vaccinium corymbosum L.) is a globally important specialty crop, and maintaining high productivity in blueberry systems depends in part on proper N management. Nitrogen can be provided by applying fertilizers or through mineralization of soil organic matter (SOM); however, the amount of N released through mineralization of SOM is difficult to predict and is not always considered in development of N fertility programs. This thesis covers the knowledge gap of N mineralization in high organic matter soils and how N release from SOM might impact northern highbush blueberry plants. Two experiments were conducted to: (1) identify N application rates that maximize fruit quality and yield and understand how optimal N rates change across soils with different SOM contents and (2) identify soil properties that are predictors of N mineralization from SOM that work in high organic matter soils and are cost-efficient, rapid, and scalable to commercial grower service laboratories. The first experiment had three N fertilizer treatments, including low (33-50 kg N ha-1), medium (67-84 kg N ha-1), and high (102-118 kg N ha-1) rates of N, that were applied for 2 years in 4 mature, commercial 'Duke' blueberry fields that were located in northwest Washington representing a range of soil organic carbon (SOC) contents 3-28%. Results suggested there was substantial N mineralization throughout the growing season at sites with higher SOM; however, higher N rates were not required to maximize fruit yield and quality at sites with lower SOM. Even the lowest N rates within this study appeared to be sufficient for production. The second experiment studied 10 soils collected from commercial blueberry fields in northwest Washington with varying levels of SOC (3-43%). These soils were incubated for 6 months, and several potential predictors of net N mineralization were evaluated. Findings from the second study suggested that soil total N is a reasonable predictor of potentially mineralizable N in high organic matter soils. As total N analysis is already available from most commercial grower service laboratories, growers may be able to adjust N application rates based on the test with little cost or additional time.



Nitrogen Fertigation Practices to Optimize Growth and Yield of Northern Highbush Blueberry (Vaccinium Corymbosum L.)

Author : Oscar L. Vargas

Publisher :

Page : 197 pages

File Size : 34,56 MB

Release : 2015

Category : Blueberries

ISBN :

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Northern highbush blueberry is a long-lived perennial crop that is well adapted to low soil pH conditions. The plants are often shallow rooted and absorb primarily the ammonium (NH4) form of nitrogen (N) rather than nitrate-N (NO3-N). Traditionally, commercial blueberry fields have been irrigated with overhead sprinklers and fertilized using granular sources of NH4-N. However, many new plantings of blueberry are irrigated by drip and fertigated by injecting liquid sources of N directly through the drip system. Three studies were conducted in western Oregon to compare fertigation to granular fertilizers and to develop methods to enhance the potential benefits of the practice. The first study was conducted in an established planting of 'Bluecrop' blueberry during the first 5 years of fruit production (year 3-7). Liquid sources of ammonium sulfate or urea were injected through a drip system in equal weekly applications from mid-April to early August. Granular sources of the fertilizers were applied on each side of plants, in three split applications from mid-April to mid-June, and washed into the soil using microsprinklers. Each fertilizer was applied at three N rates, which were increased as the plants matured (63 to 93, 133 to 187, and 200 to 280 kg·ha−1 N) and compared with non-fertilized treatments (0 kg·ha−1 N). Yield was 12% to 40% greater with fertigation than with granular fertilizer each year as well as with ammonium sulfate than with urea during the fourth year. Leaf N concentrations were also greater with fertigation in 4 of 5 years and greater with ammonium sulfate than with urea each year. The plants produced fewer roots with fertigation than with granular fertilizer, but the median lifespan of the roots was 60 days longer with fertigation. Soil pH declined with increasing N rates and was lower with granular fertilizer than with fertigation the first 3 years and was lower with ammonium sulfate than with urea in all but one year. Total yield averaged 32 to 63 t·ha−1 in each treatment over the first 5 years of fruit production and was greatest when plants were fertigated with ammonium sulfate or urea at rates of at least 63 to 93 kg·ha−1 N per year. The second study was conducted to evaluate the use of conventional drip and alternative micro irrigation systems in six newly planted cultivars ('Earliblue', 'Duke', 'Draper', 'Bluecrop', 'Elliott', and 'Aurora') of northern highbush blueberry. The drip system included two lines of tubing on each side of the row with in-line drip emitters at every 0.45 m. The alternative systems included geotextile tape and microsprinklers. The geotextile tape was placed alongside the plants and dispersed water and nutrients over the entire length. Microsprinklers were installed between every other plant at a height of 1.2 m. Nitrogen was applied by fertigation at annual rates of 100 and 200 kg·ha−1 N by drip, 200 kg·ha−1 N by geotextile tape, and 280 kg·ha−1 N by microsprinklers. By the end of the first season, plant size, in terms of canopy cover, was greatest with geotextile tape, on average, and lowest with microsprinklers or drip at the lower N rate. The following year, canopy cover was similar with geotextile tape and drip at the higher N rate in each cultivar, and was lowest with microsprinklers in all but 'Draper'. In most of the cultivars, geotextile tape and drip at the higher N rate resulted in greater leaf N concentrations than microsprinklers or drip at the lower N rate, particularly during the first year after planting. By the third year, yield averaged 3.1 to 9.1 t·ha−1 among the cultivars, but was similar with geotextile tape and drip at either N rate, and was only lower with microsprinklers. Overall, drip was more cost effective than geotextile tape, and fertigation with 100 kg·ha−1 N by drip was sufficient to maximize early fruit production in each cultivar. Microsprinklers were less effective by comparison and resulted in white salt deposits on the fruit. The final study was conducted in a new planting of 'Draper' blueberry to identify methods to increase the efficiency of fertigation with N fertilizer. Previous research indicated that more N was needed by fertigation during first year or two after planting because, unlike granular fertilizer, which could be applied by hand around the base of the plants, at least half of the N injected through the drip system was applied between the plants and beyond the root system. Twelve treatments were included in the present study, including four with different drip configurations, six with alternative fertilizers, and two to determine whether pre-plant or late-season applications of N fertilizer was beneficial with fertigation in blueberry. After 2 years, total plant dry weight was 28% to 58% greater with one or two drip lines near the base (crown) of the plants than with two lines located at 20 cm on each side of the row, even when granular or slow-release fertilizer was applied in early spring prior to fertigation with the wider drip lines. Wider drip lines often resulted in lower leaf N concentrations than other treatments and increased salinity (electrical conductivity) in the root zone. The use of alternative fertilizers such as urea sulfuric acid was effective at reducing soil pH but resulted in the same plant dry weight as liquid urea, while humic acids with N and other nutrients increased root dry weight by an average of 60% relative to any other treatment, including a control that contained the same nutrients. Pre-plant and extended N application had no measureable effect on plant growth. Overall, the results of these studies indicate that fertigation was generally more beneficial than granular applications of N fertilizer and, in new plantings, was most effective when drip lines were located near the base of the plants. Humic acids were also useful for increasing root production during establishment.



Patterns of Carbon Storage Within a Mature Northern Highbush Blueberry Production System

Author : Denise Alexandra Nemeth

Publisher :

Page : 96 pages

File Size : 37,1 MB

Release : 2013

Category : Blueberries

ISBN :

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The objectives of this study were to: 1) determine how organic matter (incorporated vs. surface mulch) and nitrogen fertilization rate impact northern highbush blueberry (Vaccinium corymbosum L.) plant biomass, carbon accumulation, plant losses and allocation, and mycorrhizal infection in mature plants, and 2) determine the magnitude of carbon fluxes (carbon net primary production (NPP), soil respiration, and fruit and pruning exports) and stocks within a blueberry production system, and how these are affected by typical management practices. Treatments were in effect for nine years since planting establishment; here we report on data collected in 2011 and 2012. Many of these treatments seem to have short- and long-term effects on blueberry plants. Long-term effects included the impact of pre-planting incorporation of sawdust, which as a main effect, had an overall positive effect on yield, and soil fertility, with all soil nutrients being above recommended sufficiency levels for blueberry production. Soil pH was increased by incorporation, and was affected by an incorporation by mulch interaction where incorporated bare plots had the highest pH, and the largest average plant dry weight and carbon (C) mass (3.5 and 1.7 kg/plant, respectively) despite the pH being above the recommended level for blueberry production. Incorporated plots in general, had a higher total field C stock averaging 97.6 t·ha −1 for mulched plots and 93.7 t·ha−1 for bare plots. Mulching as a C stock contributed 12.3 t·ha−1, 13% of the total C stock. Mulching as main treatment effect was not found to be beneficial in terms of increasing plant and soil C stocks. Although mulching did increase soil organic C in 2012, this did not seem to affect total soil C stocks, perhaps because soil respiration was also increased by the mulch. Nitrogen fertilizer rate did not affect plant biomass or C stock, nor did it affect soil C stocks and nutrients. Net primary productivity averaged 588 g·m−2.year and was not affected by the treatments, although incorporated plots had about 25% more NPP than non-incorporated plots. Our results have illustrated that with a goal of optimizing plant growth, yield, and C stocks, blueberry production systems that include pre-plant incorporation of organic matter without addition of surface mulch and moderate rates of nitrogen fertilizer are best. In addition, a between-row perennial grass cover crop is recommended to increase field C stocks and to limit soil erosion. The information gathered in this study can be used to estimate the contribution of C storage in temperate perennial crops to global C stocks. Recommended management practices could lead to a policy system where farmers receive incentives for sustainable low C agriculture.



The Highbush Blueberry and Its Management

Author : Robert E Gough

Publisher : CRC Press

Page : 289 pages

File Size : 16,52 MB

Release : 1993-12-15

Category : Science

ISBN : 1482298007

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Book Description

Here is a book that sets forth vital information growers need to produce highbush blueberries effectively and efficiently. Written from the grower?s point of view, The Highbush Blueberry and Its Management presents technical information in a highly readable manner that is easy to understand. It helps growers make proper decisions before they plant-



Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium Corymbosum L.)

Author : Khalid F. Almutairi

Publisher :

Page : 157 pages

File Size : 49,65 MB

Release : 2016

Category : Blueberries

ISBN :

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Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETsubscript c]), deficit irrigation at 50% ET[subscript c] (applied for the entire growing season), or full irrigation with irrigation cut-off for 4–6 weeks during early or late stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cut-off early and by > 2.0 MPa when irrigation was cut-off late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cut-off, whereas cutting off irrigation early delayed the season. Yield was not affected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cut-off late each year. Cutting off irrigation early likewise reduced yield, but only in the second year when the plants were not thinned; however, early cut-off also reduced fruit soluble solids and berry weight by 7% to 24%compared to full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water (2.5 ML·ha−1 less water per season). A second study was conducted in a 7-year-old field of certified organic highbush blueberry. Two cultivars (‘Duke’ and ‘Liberty’) mulched with either porous polyethylene ground cover (“weed mat”) or yard debris compost topped with sawdust (sawdust+compost) and each fertilized with either feather meal or fish emulsion were evaluated. One-year-old fruiting laterals were randomly-selected at three heights (top, middle, and bottom) on the east and west side of the plants. Bud, flower, and fruit development were monitored through fruit harvest. There was relatively little effect of mulch type or fertilizer source on the measured variables. Fruit harvest occurred ≈8 d after the fruit were fully blue and ranged from 2-25 July 2012 and 26 June-3 July 2013 in ‘Duke’ and from 1-20 Aug. 2012 and 17 July-7 Aug. 2013 in ‘Liberty’. Proportionally more fruit buds occurred on middle laterals than upper and lower laterals. The dates of bud swell and bud break were not affected by cultivar or lateral position. ‘Duke’ and ‘Liberty’ produced 6-8 and 7-9 flowers/bud, respectively. Fruit set was high in both cultivars, averaging ≈95%. However, 13-18% and 29-38 % of the initial set fruit dropped in ’Duke’ and ‘Liberty’ in late May to early June. Fruit ripening was more uniform within clusters in ‘Duke’ than in ‘Liberty’, and average fruit size was similar among harvests in ‘Duke’ but decreased by 25-40% between the first and last harvest in ‘Liberty’. Fruit matured 3−5 d earlier on the east side of the canopy than on the west side. The results suggest that pruning proportionally more on the lower part of the canopy than on the upper part will result in larger fruit at harvest than uniform pruning throughout the bush. The final study was conducted to determine the potential of applying micronized elemental sulfur (S°) by chemigation through the drip system to reduce high soil pH in a new planting of ‘Duke’ blueberry. The S° was mixed with water and injected weekly for 2 months prior to planting, as well as 2 years after planting, atrates of 0, 50, 100 and 150 kg·ha−1 per year, and was compared to the conventional practice of incorporating prilled S° into the soil prior to planting (two applications of 750 kg·ha−1 each). Chemigation quickly reduced soil pH (0-10 cm) within a month from 6.6 with no S° to 6.1 with 50 kg·ha-1 S° and 5.8 with 100 or 150 kg·ha−1 S°. The change was short-term, however, and by May of the following year, soil pH averaged 6.7, 6.5, 6.2, and 6.1 with each increasing rate of S° chemigation, respectively. The conventional treatment, in comparison, averaged 6.6 on the first date and 6.3 on the second date. In July of the following year, soil pH ranged from an average of 6.4 with no S° to 6.2 with 150 kg·ha−1 S° and 5.5 with prilled S°. Soil pH declined thereafter to as low as 5.9 with additional S° chemigation and at lower depths (10-30 cm) was similar to the conventional treatment. None of the treatments had any effect on winter pruning weight in year 1 or on yield, berry weight, and plant dry weight in year 2. Chemigation with S° can be used to quickly reduce soil pH following planting and, therefore, may be a useful practice to correct high pH problems in established blueberry fields. However, it was less effective and more time consuming than applying prilled S° prior to planting.



The Effect of Pre-plant Incorporation with Sawdust, Sawdust Mulch, and Nitrogen Fertilizer Rate on Soil Properties and Nitrogen Uptake and Growth of 'Elliott' Highbush Blueberry

Author : Linda Dee White

Publisher :

Page : 126 pages

File Size : 11,79 MB

Release : 2006

Category : Blueberries

ISBN :

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The effect of incorporated sawdust, sawdust mulch and nitrogen (N) fertilizer rate on soil nutrients and other properties, N uptake, and plant growth in a young blueberry planting on a silt loam soil type was studied in 2004 and 2005.?Elliott? highbush blueberry plants were established on raised beds that were either constructed with the incorporation of a fir sawdust amendment, or left un-incorporated. Plots were then mulched with sawdust or left bare after planting. Nitrogen fertilizer, depleted 15N ammonium sulfate, was applied at three rates, 22, 68, and 114 kg·ha-1 of N in the first year, with non-labeled N fertilizer applied in the second year at the same rates. There was a wider range in soil temperature in plots incorporated with sawdust and mulched, from -2 ðC in winter to 41 ðC in summer, than in un-mulched plots. Sawdust mulch did not appear to mitigate summer or winter soil temperatures. Incorporated plots required 5-6 times more irrigation water than non-incorporated plots during the growing season. Soil pH was reduced with higher rates of application of fertilizer N, but incorporating sawdust or mulch minimized the reduction in pH. Soil phosphorus concentration was reduced in incorporated plots. The reduction in pH and incorporating sawdust significantly lowered soil P. Preplant incorporation with sawdust increased soil organic matter by 50% the first year. Plant shoot and whip growth rate in both years was increased by mulching compared to un-mulched plots. There was a significant incorporation by mulch interaction for whip growth in 2004 and total dry weight and biomass partitioning in both years. Whip growth rate on plants in un-incorporated, mulched plots was higher than in all other treatments, peaking at 1.2 cm·d-1. Total plant dry weight was greatest in unincorporated, mulched plots. Nitrogen fertilizer rate had no effect on total plant dry weight or partitioning. Total N uptake was greatest in un-incorporated plots, but the proportion of N derived from the fertilizer (NDFF) was highest in plants growing in incorporated, un-mulched plots, up to 54% NDFF. Overall, plant growth was reduced with the addition of pre-plant incorporated sawdust and no mulching in this soil type.





Suitability of Diverse Composts as Soil Amendments for Highbush Blueberry (Vaccinium Corymbosum L)

Author : Ryan C. Costello

Publisher :

Page : 131 pages

File Size : 19,37 MB

Release : 2012

Category : Blueberries

ISBN :

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Highbush blueberry (Vaccinium corymbosum L.) is adapted to soils with high organic matter and acidic pH. Composts provide organic matter and nutrients for growing blueberry in mineral soils, but many composts are high in pH and soluble salts. Acidification with elemental sulfur (S°) can remedy high pH, but the process further increases compost salinity. The objectives of this study were to: i) determine the effects of diverse composts on blueberry growth and nutrient uptake, ii) determine whether S° acidification can ameliorate the negative effects of high compost pH, and iii) develop and validate a simple titration method to determine pH buffering capacity of compost. In our first study, ten composts were evaluated under greenhouse conditions with one-year-old blueberry. Each compost was either acidified or not with S° and then mixed 30% by volume with silt loam soil before planting. Controls were sawdust incorporation or soil only. Plants were managed with a low rate of fertilization to emphasize compost effects on nutrient supply. Compost inorganic nitrogen (N) ranged from 0.1 to 4.1 g·kg−1, and NO3-N to NH4-N ratios were greater than 20:1. Aboveground plant growth and nutrient uptake, including N, phosphorous (P), potassium (K), and boron (B) were higher in soil with compost than in soil with sawdust or soil only. Composts with pH 7.5 produced more shoot growth than those with higher pH, and composts with EC 2 dS·m−1 produced less root growth than those with lower EC. Adding S° reduced compost pH by an average of 1.9 units, and acidification increased shoot and root growth in the composts as well as uptake of many nutrients. Plant growth and N uptake were not correlated with compost N supply. Composts with greater amounts of plant-based feedstocks produced more total shoot growth than manure-based composts. In our second study, 3.7 L blueberry transplants were grown outdoors for 119 d in pots containing compost and soil. Manure feedstocks included separated dairy solids or horse stall cleanings. Plant feedstocks included urban yard trimmings, leaves from street sweeping, conifer bark conditioned with municipal biosolids, or peppermint distillation residue. Control treatments were sawdust amendment or soil only. Plant-based compost treatments had less effect on soil pH and produced 20% greater plant growth than manure-based compost treatments. Plant growth was not different with plant-based composts vs. the sawdust amendment control. Elemental S addition at potting did not acidify soil enough to overcome the increase in pH resulting from compost addition. In our third study, we titrated eight composts with dilute H2SO4 to predict response to S° acidification. Our objective was to develop and validate a simple method to determine the pH buffering capacity of compost. Compost pH decreased linearly with laboratory acid addition. Compost pH buffering capacity (linear slope of titration curve) was 0.16 to 0.39 mol H per kg dry compost per pH unit. To determine correlation between titration and S° acidification, composts samples were incubated with S° at 22° C for 70 d. The majority of the decrease in pH from S° addition occurred within 28 d. Compost pH at 28 d was closely predicted by the laboratory titration. Because of the linearity of compost response to acid addition, a 2-point titration method (one rate of acid addition) is an effective alternative to the 7-point method we used. We conclude that compost pH is the primary limiting factor affecting blueberry response to compost. Compost incorporation provided benefit to blueberry, especially under low N management, and generally increased plant growth and nutrient uptake when compared with plants grown in mineral soil only. Composts made from plant-based feedstocks, rather than manure-based feedstocks, tend to have characteristics which favor blueberry growth, including low buffering capacity, pH, and soluble salts. Feedstocks which showed promise include deciduous leaves, yard debris, bark, and horse bedding with low manure content. Acidification of composts with S° increased plant growth and nutrient uptake, and is a promising technology for eliminating the negative effects of high compost pH. Our method of laboratory titration with dilute acid addition was effective in determining pH buffering capacity of compost, and predicted the compost acidification by S° and the effect of compost on soil pH.