Fertilizer Phosphorus in Lowbush Blueberries: Effects and Fate

Eaton, L. J. and Nams, V. O. 2006. Second cropping of wild blueberries -Effects of management practices. Can. J. Plant Sci. 86: 1189-1195. Wild blueberries (Vaccinium angustifolium Ait.) are normally managed on a biennial basis. Pruning forces the plant into a vegetative year without fruit, followed by the first crop year, which provides the greatest harvest. In subsequent years, harvest levels drop dramatically. Prior to the introduction of selective herbicides, second crop yields were too low to allow the adoption of a double harvest. This study was initiated to compare production and incomes of a single cropping (2-yr management cycle, the present system) versus a double cropping system (3-yr management cycle), using systems that include herbicides. Total yields and net incomes over the 12-yr study were affected by fertilizer applications, but not by management system (2-yr management cycle versus 3-yr management cycle) or pruning (burning versus mowing). Yields in second crop plots were lower than those in first crop plots, even though blossom numbers were higher. Fertilizer affected many aspects of blueberry plant development, including stem length, numbers of buds and blossoms, and fruit yields. Over time, yields and net incomes in the 3-yr management cycle were similar to those for the standard 2-yr management cycle. L'élagage plonge la plante dans un état végétatif pendant une année durant laquelle elle ne donne pas de fruits. L'année suivante se caractérise par la récolte la plus abondante. Ensuite, le nombre de fruits baisse de manière draconienne. Avant l'arrivée des herbicides sélectifs, le rendement de la troisième année était trop faible pour qu'on songe à adopter un système de double récolte. Les auteurs ont entrepris une étude afin de comparer la production et le revenu venant d'un régime à récolte unique (cycle de deux ans, comme c'est le cas présentement) à ceux d'un régime à double récolte (cycle de trois ans) recourant aux herbicides. Le rendement global et le revenu net relevés lors de cette étude de 12 ans ont été affectés par les applications d'engrais, mais pas par le système cultural (cycle de deux ans contre cycle de trois ans) ni par l'élagage (brûlis contre tonte). Le rendement des parcelles de trois ans était plus faible que celui des parcelles de deux ans, malgré une floraison plus abondante. La fertilisation affecte maints aspects du développement de la plante, notamment la longueur des tiges, le nombre de bourgeons et de fleurs, et le rendement fruitier. Avec le temps, le rendement et le revenu net issus du cycle de trois ans se rapprochent de ceux observés pour le cycle de deux ans.

Section: Discussioncontrasting

confidence: 98%

Second cropping of wild blueberries — Effects of management practices

Eaton¹,

Nams²

2006

“…It is evident that increased levels of soil-applied P had no effect on plant growth (total stem length) or reproductive parameters (total number of buds, blossoms per stem and fresh fruit yields). Similar effects of fertilizer applications, especially where herbicides were applied, were reported by Eaton (1994) and Eaton et al (1997). This is in contrast to results reported by Smagula and Dunham (1995) where they indicated increased vegetative growth and yield from applications of DAP.…”

Section: Resultssupporting

confidence: 80%

“…The results demonstrate a clear pattern of increased levels of Mehlich-3 extractable P in plots receiving higher rates of soil-applied fertilizer P, following a lag period of at least 2 yr (one production cycle) after the initial fertilizer applications. Similarly, Eaton (1994) and Eaton et al (1997) noted increased levels of extractable P in soils amended with a phosphorus-containing fertilizer. Mean soil levels for K, Ca and Mg were not affected by treatment, and were in the ranges of 32Á43, 159Á264 and 23Á44 mg g (1 , respectively.…”

Section: Resultsmentioning

confidence: 87%

“…Prior to 1990, most fertilizers applied to wild blueberries contained only nitrogen, but in recent years phosphorus and potassium have been included in formulations such as 13-26-5, 9-46-0 and 18-46-0 (Eaton et al 1997). Wild blueberry yields and plant responses in most short-term studies have been inconsistent (Eaton et al 1997;Litten et al 1997;Smagula and Dunham 1995). A long-term study demonstrated increased stem lengths and fruit bud numbers after three or more cycles where a N-P-K fertilizer was applied in conjunction with herbicide (Eaton 1994).…”

mentioning

confidence: 99%

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Wild blueberry response to phosphorus applied to Prince Edward Island soils

Sanderson¹,

Eaton²

2008

Self Cite

Pressure on growers to protect the environment and reduce input costs has increased the need to more effectively use fertilizers. Two experiments were conducted to evaluate the response of wild blueberries to soil-applied P on loamy sand to sandy loam Orthic Podzol soils in Prince Edward Island over three cropping cycles from 1992 to 1997. The sites had soil test (Mehlich-3) P levels from 33 to 44 µg P g-1, which are rated as L- for blueberries in the PEI Soil and Feed Testing Laboratory Standards. Treatments consisted of soil-applied P at 0, 10, 20, 30 and 40 kg ha-1 applied to the same plots in the sprout year in each of three consecutive cropping cycles. There was a positive linear relationship between application rate of P and extractable soil P and leaf tissue P concentration. Over the 6 yr of the study, soil extractable P increased on average 1.1 µg P g-1 for each kg of soil-applied P compared with the control where no soil P was applied. Increases in levels of tissue P concentration were less dramatic. Plant growth and yields were not affected by rate of soil-applied P fertilizer. This study indicates that on sites with low soil test P, application of soil-applied P did not benefit wild blueberry production. By conserving P fertilizer, growers can also reduce the potential for environmental damage caused by the buildup of soil P. Key words: Phosphorus, soil and leaf nutrient concentrations, wild blueberry, Vaccinium angustifolium Ait., yield

“…Subsequent to the initial fertilizer application in 1997, there were higher levels of Mehlich 3 extractable P in plots receiving consecutive fertilizer applications than in plots receiving alternate fertilizer applications, and similar differences were noted in the mean values (Table 2). Similarly, Eaton et al (1997) and observed increased levels of Mehlich 3 extractable P in plots amended with increased rates of a P fertilizer. The changes in mean levels between 1997 and 2003 were influenced by application timing.…”

Section: Resultsmentioning

confidence: 67%

Comparison of consecutive and alternate fertilizer applications in wild blueberry production

Eaton¹,

Sanderson²,

Fillmore³

2009

Self Cite

. 2009. Comparison of consecutive and alternate fertilizer applications in wild blueberry production. Can. J. Plant Sci. 89: 93Á98. Research has shown that improved nutrient uptake and yield of wild blueberries (Vaccinium angustifolium Ait) are very sporadic when fertilizers are applied. Growers are concerned with environment impacts and keeping fertilizer costs to a minimum. Two experiments were conducted to evaluate the response of wild blueberries to soil-applied fertilization over four cropping cycles in Prince Edward Island and Nova Scotia from 1997 to 2004. Commercial fertilizers (17-17-17, 18-46-0 and 13-26-5) were soil-applied in the sprout year either as a consecutive fertilizer application (every cropping cycle) or an alternate fertilizer application (every second cropping cycle). All fertilizers were applied at a rate of 200 kg ha (1 . Fertilizer applications increased soil levels of P and K, leaf tissue concentrations of N and P and stem lengths of plants. Higher levels of soil P and leaf tissue concentrations of N, P and K were observed with consecutive than with alternate fertilizer applications. Average stem lengths, buds and blossoms per stem were higher over the length of the study when fertilizers were applied consecutively compared with alternately. Fruit yields were increased compared with the unfertilized control. Within applied fertilizers treatments, fruit yield was not affected when fertilizer was applied in either consecutive or alternate cropping cycles. Alternate fertilizer applications may reduce soil accumulation of P and production costs without comprising yields. 93Á98. La recherche montre que l'application d'engrais entraıˆne de manie`re tre`s sporadique une meilleure absorption des e´le´ments nutritifs et une hausse du rendement chez le bleuet sauvage (Vaccinium angustifolium Ait). Les producteurs craignent l'incidence des engrais sur l'environnement tout en souhaitant maintenir le couˆt de la fertilisation au plus bas. Les auteurs ont proce´de´a`deux expe´riences afin d'e´valuer la re´action du bleuet sauvage aux engrais applique´s sur le sol pendant quatre cycles de production, a`l'Iˆle-du-Prince-É douard et en Nouvelle-É cosse, de 1997 a`2004. À cette fin, ils ont e´pandu des engrais commerciaux (17-17-17, 18-46-0 et 13-26-5) sur le sol l'anne´e de la germination, soit conse´cutivement (a`chaque cycle), soit en alternance (un cycle sur deux). Tous les engrais ont e´teá pplique´s a`raison de 200 kg par hectare. La fertilisation augmente la teneur en P et en K du sol, la concentration de N et de P dans le tissu foliaire et la longueur des tiges. Les applications conse´cutives d'engrais accroissent plus la teneur en P du sol ainsi que la concentration de N, de P et de K dans les feuilles que les applications alterne´es. Durant l'e´tude, la longueur moyenne de la tige ainsi que le nombre de bourgeons et d'inflorescences e´taient plus e´leve´s quand on a applique´les engrais conse´cutivement au lieu d'une fois sur deux. Le rendement fruitier e´tait plus e´leve´que sur la parcelle...