Spectrum Analytic Inc. FERTILIZING GRAPES Soil Analysis 1087 Jamison Road 1-800-321-1562 Plant Analysis PO Box 639 (740) 335-1562 Fertilizer Analysis Washington C.H., Ohio 43160 Fax: (740) 335-1104 Manure Analysis www.spectrumanalytic.com 2 Table of Contents Introduction ........................................................................................................................................ pg 3 Soil pH ................................................................................................................................................ pg 4 Nitrogen.............................................................................................................................................. pg 5 Phosphorus .......................................................................................................................................... pg 6 Potassium............................................................................................................................................ pg 7 Calcium............................................................................................................................................... pg 8 Magnesium.......................................................................................................................................... pg 9 Sulfur .................................................................................................................................................. pg 9 Boron.................................................................................................................................................. pg 10 Copper ................................................................................................................................................ pg 10 Iron..................................................................................................................................................... pg 11 Manganese.......................................................................................................................................... pg 11 Zinc .................................................................................................................................................... pg 12 Plant Sampling Instructions for Grapes .................................................................................................. pg 13 References.......................................................................................................................................... pg 14 3 INTRODUCTION Grapes are deep-rooted perennial crops, and because of this may not respond to fertilizer as predicted by a soil sample taken only 7 inches deep. Grape producers should monitor their crops nutrient status with periodic soil testing and annual tissue analysis. We prefer leaf analysis rather than petiole analysis because it provides a better evaluation of all nutrients. Reported values for the total nutrient uptake and removal of grapes vary somewhat. This is likely caused by differences in variety, rootstock, yield, and possibly in data collection methods. The values below are similar to other generally accepted and reported values for total uptake, but somewhat lower than some reports for crop removal of macronutrients. TOTAL NUTRIENT UPTAKE YIELD N P2O5 K2O SO4-S Ca Mg B Cu Mn Zn Fe T/a (Lb./acre) 1.0 6.8 2.8 12 n/a 11.8 1.2 .003 .0052 .004 .009 .02 11.0 75 31 132 n/a 130 13 .033 .057 .044 .098 .216 IFA World Fertilizer Use Manual, 1992 According to the IFA World Fertilizer Use Manual, “Stems and leaves, which are re-incorporated in the soil, account for about 70% of the N uptake and 60% of the P2O5 and K2O, so the net removal in the harvest is clearly much smaller”. While this may be true, remember that nutrients contained in plant residue may not be completely re-cycled in time to fully benefit the next crop. Based on the above estimate of nutrient recycling, the net removal of N, P2O5, and K2O would be as follows… MACRONUTRIENT REMOVAL YIELD (T/a) N P2O5 K2O (Lb./acre) 1.0 2.0 1.1 4.8 11.0 23 12.4 52.8 Grape producers should realize that it is not normally profitable to apply only crop removal rates of nutrients to the crop, unless the soil contains a proven, exceptionally strong ability to supply the crop with those nutrients. This proof must include recorded yields, and tissue analysis results. Remember, we are applying nutrients to the soil…not the plant! There are chemical and biological interactions that will occur in the soil to both tie -up and release nutrients that are applied, before the plant is able to absorb the nutrients. Another complicating factor in fertilizing grapes is that the grower is after both volume and quality in his crop. The correct fertilizer program for maximum volume yield may lower quality. The reverse may also be true. General Fertilizer Application Methods It is generally agreed that soil applications in established vineyards should be in a 3 to 5 ft. wide band, parallel to the row. Take care to keep the band 18” to 24” away from the base of the vines. This is most important on young vines. 4 Soil pH Grapes fall into two general categories related to pH preference. American grapes (Lambrusca) generally prefer a lower soil pH than do European varieties (Vinifera, French hybrids). University publications and other authorities differ somewhat on the ideal soil pH for the two types of grapes, especially the American varieties. These sources indicate that American grapes perform best when the soil pH is between 5.0 and 6.0, with several suggesting a soil pH of from 5.5 to 6.0. It is generally agreed that the European varieties do best with the soil pH near 6.5. The following is a list of some varieties by type: AMERICAN VARIETIES (Lambrusca) Alden Concord New York Muscat Reliance Steuben Bath Delaware Niagara Remaily Suffolk Red Buffalo Himrod Norton Schuyler Van Buren Canadice Mars Price Seneca Vanessa EUROPEAN VARIETIES (Vinifera, French hybrids) Aligote Cabernet Sauvignon Chardonnay Landot Seyval Blanc Aurore Carmine Cardonnel Merlot Vidal Blanc Baco Noir Cayuga White DeChaunac Pinot Noir Bignoles (ravat 51) Chambourcin Foch Rayon d’Or Cabernet Franc Chancellor Gewurztraminer Riesling (also called White Riesling 5 Nitrogen (N) Grapes do not have a high N requirement, when compared to many other crops. In fact, a high plant N content late in the season is often detrimental to the quality of both types of grapes, whether for jams, juice, jelly, or wine. High plant N levels late in the season can also adversely affect the vines ability to withstand a severe winter. However, inadequate N will reduce yields and profits. It is important to understand and identify the needs of a specific crop, or section of the vineyard. New Plantings There is little in the literature to suggest a different N rate for new plantings. Some sources recommend about ½ the rate of N for new plantings. However, a logical case can be made for maintaining the same, or increasing the rate of N on new plantings, since the goal is to grow vines, not grapes. The use of a higher N rate should be tempered by the possibility of having a soft succulent plant going into winter or creating a significant amount of carry-over N in the first year of bearing fruit. Established Vineyards Depending on the inherent N supplying ability of the soil, the correct N rate for a vineyard will typically range from 30 to 100 lb. N/acre, with 75 lb. N/acre being a commonly needed N application rate. One significant difference from this is when the vines are planted in the “Geneva Double Curtain” system. This system often produces best with up to twice the N rate of a single trellis design. Where a sod cover crop is present, it may require an additional 40 lb. N/acre to maintain a healthy grass stand. N Application Timing There is significant disagreement here as well. Most authorities agree that the greatest demand for N is from bud-break through early berry development. In wine producing areas such as California and Europe the recommendations are typically for a single N application prior to bud-break. This is probably so that the proper concentrations of compounds desirable for wine production form in the berries by harvest. In areas where the production is primarily for table or other uses, a split application is sometimes recommended. They typically suggest applying ½ of the N prior to bud-break and ½ post-bloom. While this is not necessarily a large difference, it could be very significant on soils with a high possibility of N leaching. Some recommendations suggest that mid-winter N applications are satisfactory. Producers that are interested in this option should consider the possibilities of N losses on their particular land and typical weather pattern. Foliar N Foliar N should not be considered a substitute for a sound soil applied program, and few authoritative sources make any recommendation for foliar N. However, where foliar N is needed the following program has been successful. Mix 5.0 lb. of low biuret urea per 100 gal. and apply at 200 gal./acre starting with the first cover spray and spacing the sprays about 10 days to 2 weeks apart. Up to 3 applications are recommended. Calcium nitrate can be applied at 5.0 – 7.0 lb. per 100 gal. Some Universities recommend that growers allow weeds and grass to grow within the rows late in the season (from September on in the Mid-west). The reasoning is that the weeds will pull N and moisture from the crop. This will slow growth, promote