Response of Blackberry Cultivars to Fertilizer Source during Establishment in an Organic Fresh Market Production System

Abstract

<jats:p>Blackberry (<jats:italic>Rubus</jats:italic> ssp. <jats:italic>Rubus</jats:italic>) cultivars, three trailing types (Marion, Black Diamond, and Obsidian) and one semierect type (Triple Crown), were studied for their response to different types of fertilizer from 2011–12, at a certified organic, grower collaborator site located in Jefferson, OR. Plants were fertilized at a target rate of 50 lb/acre nitrogen (N) each spring using three different sources: 1) a liquid fish and molasses blend (4N–0P–1.7K); 2) pelletized soy (<jats:italic>Glycine max</jats:italic>) meal (8N–0.4P–1.7K); and 3) pelletized, processed poultry litter (4N–1.3P–2.5K). Plants were drip irrigated, and weeds were managed using a polypropylene, permeable landscape fabric (weed mat). Plant responses were greatly affected by cultivar, whereas the effects of fertilizer type were relatively minor. ‘Triple Crown’ produced the greatest yield in both years, whereas ‘Black Diamond’ and ‘Marion’ had the lowest yield in 2011 and 2012, respectively. ‘Triple Crown’ fruit had the highest percent soluble solids and were the least firm in 2011, whereas ‘Marion’ fruit were the least firm in 2012. Harvest date, within year, affected the fruit quality variables measured in all cultivars. Most soil nutrient levels were within the recommended range for all fertilizer treatments, except for boron (B), which declined to deficient levels in the second year. Fertilizer type had no effect on soil nutrient levels other than fertilization with the fish and molasses blend product increased soil potassium and sodium. Soil nutrient levels were affected by cultivar but varied by year for many nutrients. Primocane leaf tissue nutrient concentrations were above or within recommended standards for most nutrients, except for magnesium (Mg), calcium (Ca), and B, which, depending on the cultivar, were below standards. Over the 2-year study, the blackberry cultivars responded similarly to the three types of organic fertilizer. However, the cost of N varied from $8.16/lb for the liquid fish and molasses blend, $5.35/lb for the pelletized soy meal, and $2.54/lb for the pelletized, processed poultry litter. Supplemental fertilization with B, Mg, and Ca would be required with each fertilizer studied to maintain recommended soil fertility levels.</jats:p>

Uptake and Partitioning of Nutrients in Blackberry and Raspberry and Evaluating Plant Nutrient Status for Accurate Assessment of Fertilizer Requirements

“…Current recommendations are to sample cultivars separately for tissue analysis (e.g., Hart et al, 2006), which has been confirmed by finding cultivar differences among primocane leaf nutrients in floricane-fruiting blackberry (Fernandez-Salvador et al, 2015a, 2015b, 2015cHarkins et al, 2014;B.C. Strik and A. Vance, unpublished data) and raspberry (John and Daubeny, 1972;John et al, 1976) and primocane-fruiting raspberry (D.R.…”

“…The most common N fertilizers applied to caneberry are calcium nitrate, urea, and ammonium sulfate in conventional systems and Organic Materials Review Institute (OMRI)-listed fish emulsion, pelletized chicken litter, soybean (Glycine max) meal, or feather meal in organic systems. In studies of certified organic blackberry, three cultivars responded similarly to equivalent rates of N applied through various sources, including fish emulsion as a liquid soil drench, pelletized chicken litter, and soybean meal when applied to the in-row area in split applications (Fernandez-Salvador et al, 2015b). Two cultivars also responded similarly to a blend of corn (Zea mays) steep liquor and fish waste digestion and a blend of fish solubles and molasses, when either blend was diluted and applied through the drip irrigation system (Fernandez-Salvador et al, 2015a).…”

“…Two cultivars also responded similarly to a blend of corn (Zea mays) steep liquor and fish waste digestion and a blend of fish solubles and molasses, when either blend was diluted and applied through the drip irrigation system (Fernandez-Salvador et al, 2015a). Organic fertilizer sources often differ in N release rate, which is an important factor to consider when targeting the crop needs (Gutser et al, 2005), soil N availability (Gale et al, 2006), and the cost (per pound of N applied) of the fertilizer (Fernandez-Salvador et al, 2015b).…”

“…Many nutrients other than N are present in organic fertilizers and are thus applied to the planting, whether required or not (Fernandez-Salvador et al, 2015a;Harkins et al, 2014;Larco et al, 2013). Fertilization with different sources of organic fertilizers, or various rates of N when using inorganic sources, may affect the con- centration of other macroand micronutrients in the plants (e.g., Chaplin and Martin, 1980;Fernandez-Salvador et al, 2015a, 2015bHarkins et al, 2014;Naraguma and Clark, 1998;Spiers and Braswell, 2002).…”

Seasonal Variation in Leaf Nutrient Concentration of Northern Highbush Blueberry Cultivars Grown in Conventional and Organic Production Systems

“…Cultivars of blackberry (Fernandez et al, 2015;Harkins et al, 2014;Strik, 2015), raspberry (John et al, 1976) and blueberry (Eaton and Meehan, 1971) have been shown to differ in leaf nutrient levels when sampled in midseason. In contrast, Clark et al (1988) found no difference among blackberry cultivars that had a similar parentage.…”