Uptake, Partitioning, and Storage of Fertilizer Nitrogen in Red Raspberry as Affected by Rate and Timing of Application

Abstract

<jats:p>The effects of <jats:sup>15</jats:sup>N-labeled fertilizer applied to mature summer-bearing red raspberry (<jats:italic>Rubus idaeus</jats:italic> L. `Meeker') plants were measured over 2 years. Four nitrogen (N) treatments were applied: singularly at 0, 40, or 80 kg·ha<jats:sup>-1</jats:sup> of N in early spring (budbreak), or split with 40 kg·ha<jats:sup>-1</jats:sup> of N (unlabeled) applied at budbreak and 40 kg·ha<jats:sup>-1</jats:sup> of N (<jats:sup>15</jats:sup>N-depleted) applied eight weeks later. Plants were sampled six times per year to determine N and <jats:sup>15</jats:sup>N content in the plant components throughout the growing season. Soil also was sampled seven times per year to determine inorganic N concentrations within the four treatments as well as in a bare soil plot. There was a tendency for the unfertilized treatment to have the lowest and for the split-N treatment to have the highest yield in both years. N application had no significant effect on plant dry weight or total N content in either year. Dry weight accumulation was 5.5 t·ha<jats:sup>-1</jats:sup> and total N accumulation was 88 to 96 kg·ha<jats:sup>-1</jats:sup> for aboveground biomass in the fertilized plots in 2001. Of the total N present, averaged over 2 years, 17% was removed in prunings, 12% was lost through primocane leaf senescence, 13% was removed through fruit harvest, 30% remained in the over-wintering plant, and 28% was considered lost or transported to the roots. Peak fertilizer N-uptake occurred by July for the single N applications and by September for the last application in the split-N treatment. This uptake accounted for 36% to 37% (single applications) and 24% (last half of split application) of the <jats:sup>15</jats:sup>N applied. Plants receiving the highest single rate of fertilizer took up more fertilizer N while plants receiving the lower rate took up more N from the soil and from storage tissues. By midharvest, fertilizer N was found primarily in the fruit, fruiting laterals, and primocanes (94%) for all fertilized treatments; however, the majority of the fertilizer N applied in the last half of the split application was located in the primocanes (60%). Stored fertilizer N distribution was similar in all fertilized treatments. By the end of the second year, 5% to 12% of the fertilizer acquired in 2001 remained in the fertilized plants. Soil nitrate concentrations increased after fertilization to 78.5 g·m<jats:sup>-3</jats:sup>, and declined to an average of 35.6 g·m<jats:sup>-3</jats:sup> by fruit harvest. Seasonal soil N decline was partially attributed to plant uptake; however, leaching and immobilization into the organic fraction may also have contributed to the decline.</jats:p>

Looking beyond fertilizer: assessing the contribution of nitrogen from hydrologic inputs and organic matter to plant growth in the cranberry agroecosystem

“…Other perennial fruit crops also have relatively low rates of fertilizer N uptake. Raspberries, with a perennial rootstock and a biennial top, derived 13-36% of N from fertilizer (Rempel et al 2004). In a study with perennial pecan trees, 28% of 15 N labeled fertilizer was found in the plant, 24% in the soil, and 48% was lost to the environment (Rey et al 2006).…”

Soil Inorganic Nitrogen Content and Indices of Red Raspberry Yield, Vigor, and Nitrogen Status as Affected by Rate and Source of Nitrogen Fertilizer

“…Biomass of fruiting clusters (Dean et al 2000) and of whole floricanes (Kowalenko 2003) were used as indices of relative berry yield. Primocane length and diameter and mean primocane dry weight were used as indices of primocane vigor (Zebarth, Freyman, and Kowalenko 1993;Dean et al 2000;Rempel, Strik, and Righetti 2004). Fruiting cluster and whole floricane N concentration and N accumulation at onset of commercial berry harvest, dormant floricane N concentration, and primocane N concentration were used as indices of crop N status.…”

“…In Oregon, Chaplin and Martin (1980) found no significant effect of N fertilization rate on yield of red raspberry over a 5-year period, whereas Rempel, Strik, and Righetti (2004) measured a yield response in the second year of a 2-year experiment. In Scotland, N fertilization increased yield in the first 2 cropping years, had no effect on yield in the subsequent 3 years, and decreased yield in the final 2 years, suggesting that N requirements and consequently yield response to N fertilization may vary depending on the age of the crop (Lawson and Waister 1972).…”

“…This lack of response to N fertilization may be due to several factors: a relatively low crop N demand due to limited plant density (Kowalenko 1994), a large supply of N from soil N mineralization, particularly where manure was applied (Dean et al 2000), difficulty in measuring crop response to N-fertility treatments due to high inherent variation in the crop (Kowalenko 2003), or to the ability of Rubus species to remobilize significant quantities of N from storage tissues (Mohadjer et al 2001;Rempel, Strik, and Righetti 2004). Using 15 N, Rempel, Strik, and Righetti (2004) reported that increasing fertilizer-N rate did not significantly increase plant N uptake but increased the proportion of N taken up from fertilizer and decreased the proportion of N from soil and from storage tissues. The lack of consistency in the response of the measured crop parameters to N-fertilization rate suggests that plant-based indices based on single-year crop N response may not be suitable for evaluating N-fertility management of red raspberry under the high N-fertility conditions present in this study.…”

Simulating Nitrate Leaching Profiles in a Highly Permeable Vadose Zone

“…Finally, the fertilization practices are also important in terms of quantity and timing [37], and this can greatly affect nitrate leaching. For example, an important rainfall Fig.…”