Black Walnut Tree:


Dr.Akhtar Khwaja PhD CPC, CPAg/SS

K Laboratories International Inc, Oshkosh, WI, USA





The decision to grow a tree crop is difficult one. There are number of factors that are needed to follow: price, yields, inflation rates, long-term demand and supply and exchange rates.  These factors can individually or collectively cause investment to be either a profit success or disaster.


This report will highlight the production related problem and how to improve the growth of trees by high tech management. This paper will also cover the information related to the culture of patented black walnut cultivars, growth rates and how to improve the growth rates by nutrients and soil fertility management.


Site Selection:


It is important that soil selection must be suitable for growing black walnut trees. I have a client in Florida who selected very heavy soil with very low pH and high trace mineral. It took as much as three years to fix that type of soil for optimum growth of black walnut tree. In the first few years, the tree grew low and went into dormancy every August, leaving the health of the tree very questionable.  After application of several soil amendment techniques, the tree started showing positive growth. This kind of mistake can set the project delay and slow tree growth.


The site selection depends on the soil structure, soil physical characteristics, pH, and availability of major and minor elements.


The black walnut trees grow in pH ranging from 6.5 to 7.5 and sometime put-up three to five growth in one year. It is notice in many soils the tree grows very fast and it was a problem because the tree stem could not take the weight of the stem and leave. Therefore it is important to maintain the growth according to the soil types and development of roots. It is very important to have some understanding of roots and shoots ratio, which is highly depending on the physical characteristic of the soil.


Soil Phosphorus levels are very important for the tree to develop strong tree trunk, and the availability of phosphorus is highly depended on the pH of soil and soil structure. Soil with high organic matter will increase the growth but tree is bend in third and fourth year. It is important to balance the nitrogen, potassium, calcium and potassium ratio in order to keep the tree service for long time.


Black Walnut tree plantation is designed for long-term investment. It must be taken under consideration for selecting the site that the tree would be in the area for long term and would not effect the other farm operations.

Site selection should be based on location of farm and the physical and chemical characteristics of the soil.


Good Soil for Black Walnut Tree:

Ideally good soil is with high organic matter, very will drain, rich, deep aerated soil and have good moisture holding capacity. If the soil is very well drained, it will help the tree put more roots and deep roots. The problem with well-aerated soil is that the nutrients leach and continuous nutrients are needed to be applied for maintaining the health of trees.


Other Important Factors of growing good Black Walnut tree is to apply liming, nitrogen, phosphorus, and potassium fertilizer.


A good fertilizer and soil amendment recommendation for Black walnut tree in soil with neutral pH and medium levels of soil phosphorus, potassium and sulphur is the application of 1000 ponds per acre of Gypsum, and 450 ponds per acre of NPK fertilizer at the ratio of 6-24-24. High nitrogen applications on Black walnut tree is not necessary after three years and even in some soil after two years it is not necessary to apply high nitrogen containing fertilizer. It increases lodging, and breaking the tips and sometime whole trees.


Soil Calcium and Magnesium ratio:


It is very important to mention that we have seen the Black Walnut grow very well in ratio of one to seven of Ca/Mg. If the ratio of calcium and magnesium decreases then the tree lodging is noticed on many projects. It was also noticed on many soil tests that when the high magnesium in ratios were reduced and retarded the root developments. Root developments were slow and some time fertilizer applications have not given any positive response.


Therefore selection of the soil with proper calcium and magnesium ration is very important for optimum growth of black walnut trees.


In this report I have included soil tests of black walnut tree, and fertilizer recommendation provided by K Laboratories International, Inc. This lab has specialized in soil tests for high value crops and developing highly specific recommendation for trees and high value crops. Enclosed is the list of hundreds of growers who are using the K Labs. Laboratory data to make good decisions for their black walnut trees growth and development projects.


Once the cultivars are selected and if it high breed grafted and patented by Dr. Walker Beineke, than the growth rate of tree would be 500 to 1000 times more under proper nutrient management program. I am presenting some picture, which under better cultivars and nutrient and soil fertility management program. The growth of trees was fast and manageable.


Since it takes 25 to 30 years for the tree to reach maturity, our goal is to improve the soil fertility and management technique and keep the desirable height and diameter and strength of the trees. The time of maturity can be reduced by 20 to 30 %.


It has been done on plants like ginseng and cranberry, just the nutrients, and cultivars changed and introduced the high tech management has reduced the time factor by 30 to 40%.  This is also possible in tree crops such as black walnut tree.


Planting methods and taking care of the tree have been developed by the American forestry and details are available in many publications that are available from AFT.


Rate of growth:


Present rate of growth is 20 to 25 inches diameter and 75 to 80 feet height.  By improving the diameter in soils with high phosphorus and potassium and balance calcium and magnesium ratio the growth can be improved by 25 percent. Various projects are under way under different soils and locations to reduce the maturity time and increase the diameter of trees trunk.


Important factors may improve the Black walnut growth and diameter of tree.


a.      Planting on high pH, sandy soils, well drained

b.     High phosphorus and high Organic matter

c.     Calcareous soil with drip irrigation

d.     Watering the tree when needed

e.      Location, hot climate

f.       Tree shelters

g.     Prevent from damage

h.     Proper weed control

i.        Pest Control

j.        Water Management



Expected Return:


As everyone knows that the tree plantation is not a fast return, but with proper management and technology return can be secured and a tree price can be ranged $ 3000 to $15,000 in 20 to 25 years.


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