|Yin, Xinhua - UNIV OF TENNESSEE|
|Seavert, Clark - OREGON STATE UNIV|
Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 10, 2009
Publication Date: June 10, 2009
Citation: Yin, X., Bai, J., Seavert, C.F. 2009. Pear responses to split fertigation and band placement of nitrogen and phosphorus. HortTechnology. 19(3):586-592. Interpretive Summary: Nitrogen (N) and Phosphorus (P) applications reduced by 20% of the current broadcast application rates and fertigated in five equal split applications each season, can supply bearing pear trees with adequate N and P nutrition without resulting in any reduction in soil indigenous N and P supply. Shift from the current N and P management practice – single broadcast application on the soil surface to split fertigation showed significant beneficial effects on fruit size, reduction in fruit superficial scald, and increase in N and P fertilizer use efficiency. Band placement of N and P increases fruit size and reduces fruit superficial scald when compared with broadcast application, with soil disturbance caused by band placement. Overall, our results suggest that split N and P fertigation and band placement of N and P improve tree N and P nutrition, pear quality and storability, and the use efficiency of applied N and P is better relative to our current N and P management practice. We expect split N and P fertigation practices will be used in commercial pear production to reduce fertilizer costs, fertilizer application costs, soil compaction, and water pollution in the Mid-Columbia region of Oregon.
Technical Abstract: Split fertigation and band placement of N and P may increase the use efficiency of applied N and P compared with the current N and P management practice -- single broadcast application of N and P on the soil surface. A field experiment was conducted from 2005 through 2006 to evaluate the effects of split fertigation and band placement as alternate N and P management practices in 'd'Anjou' pears growing on a Parkdale loam soil near Parkdale, Oregon.Measurement and analysis of tree nutrition, fruit yield, quality, storability and indigenous soil nutrient supply was the scope of the experiment. To evalaute fertilizer management practices on pear growth and yield, the following four treatments were tested with a randomized complete block design replicated four times: 1) broadcast application of N and P on the soil surface, 2) band placement of N and P on both sides of a tree row in a 30-cm (width) × 30-cm (depth) ditch, 3) broadcast application of N and P to the soil surface which was digged a 30-cm × 30-cm ditch using the band placement equipment, then the digged soil was completed returned to the ditch without any fertilizer being banded, and 4) fertigation of N and P split into five equal applications throughout the growing season. Nitrogen and P fertilizers were applied to treatments 1, 2, and 3 at 112 kg N ha-1 and 140 kg P2O5 ha-1, while treatment 4 received only 90 kg N ha-1 and 112 kg P2O5 ha-1. Leaf N and P concentrations in the fall were increased by 10.0% and 10.6%, respectively, with split fertigation, compared with broadcast application on the soil surface. Band placement increased leaf N by 7.1% relative to broadcast application on the soil surface with soil disturbance caused by band placement. Split fertigation and band placement both slightly increased fruit yield, but significantly increased marketable fruit (the total of excellent and very slightly scalded fruit) by 20.9% and 11.1% (absolute value) when compared with broadcast application of N and P and broadcast application of N and P with soil disturbance caused by band placement, respectively, and after 3 months cold storage. No detrimental effects on fruit weight or reduction in soil amino sugar N were observed from lowering both the N and P application rates by 20% with split fertigation. Overall, split fertigation and band placement of N and P improved tree N and P nutrition, pear quality and storability, and the use efficiency of applied N and P relative to the current N and P management practice – single broadcast application of N and P on the soil surface on pear orchards in the Mid-Columbia region, Oregon.