Cultural practices have been very simple at the Station. After planting, the trees were cultivated for a year or two, then the space between sown to grass and clover and the space just around the trees was mulched with manure, hay, etc. The grass is cut several times a year and placed around the trees as additional mulch. Small quantities of a good commercial fertilizer such as 4-8-10 have been applied occasionally and some nitrogen also has been used.
Pruning has been reduced to a minimum, a light thinning out of branches being given as required. Very little attempt has been made to keep filberts to a single stem, but the walnuts have been kept to a single low-headed trunk.
There has been a marked increase in interest in the planting of nut trees in Ontario since the first plantings were made at the Station. These Station plantings serve to demonstrate in a small way that nut trees can be grown in the Niagara fruit belt of Ontario. The feasibilty, however, of growing nut crops in a commercial way, even in this district, is still open to question, although it is felt that farmers and others should be encouraged to plant a few nut trees on their property both for the sake of the nuts and because of the ornamental nature of the trees.
Soil Management for Nut Plantations in Ontario
J. R. van HAARLEM, Horticultural Experiment Station, Vineland Station, Ontario
Fruitgrowers with high priced land, such as we have in the Niagara Peninsula, are not much interested in using such land for a crop not yet proven commercially sound. Plantings, whether large or small, are likely to be made on low-priced marginal land needing good care. It is doubtful if these locations are best suited to proper nut culture since most nut trees are deep rooted with extensive root systems requiring the best soils.
At the Vineland Station we have three plantations made up of 110 walnuts, 240 filberts, 14 chestnuts and 6 pecans. These comprise named varieties and seedlings of black, Carpathian, and other Persian walnuts, filberts, chestnuts and pecans.
During the first years of the life of these plantations we maintained a clean cultivation program during the spring and early summer followed by the planting of a green-manure crop about July 1st each year. Such crops as buckwheat, millet, rye, and weeds, have been used on occasion. We soon found that the treatment was not good enough for the trees and we then changed to a grass sod with mulch around each tree within the spread of the branches. Since this sod-mulch treatment was applied the trees have done very much better, making fine growth and maintaining a large leaf area of good color. This treatment is fairly representative of the many trees planted in dooryards under sod conditions, where the grass is cut and left on top.
Most of our Ontario soils are deficient in organic matter and, depending on location, deficient in phosphate or potash, or both together. The mineral deficiency should first be corrected by liberal applications of the required fertilizer before placing the plantations in sod, in fact it would pay to do this several years before setting out the trees, growing alfalfa on this land and returning all the hay back into the soil. For plantations already set out these minerals could be placed in a furrow cut just under the outer spread of the branches. Our soils have a high fixation factor for phosphate and potash and we have found that the best practice is to place the fertilizer under the surface either with a deep-placement machine or as outlined above.