Potential Fertility Issues with Excessive Rain? Pecan Fertilization and Excessive Rains. Does Excessive Rain affect Fertility? How Much is Too Much?

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1 Pecan Fertilization and Excessive Rains ALLAN C. THORNTON EXTENSION ASSOCIATE HORTICULTURAL SCIENCE NORTH CAROLINA STATE UNIVERSITY Potential Fertility Issues with Excessive Rain? Nitrogen Potassium Magnesium Sulfur ph Does Excessive Rain affect Fertility? How Much is Too Much? Does Excessive Rain affect Fertility? Surface Erosion Leaching Denitrification How Much is Too Much? Florence Rain Reports (inches) Elizabethtown 36 Swansboro 34 Oak Island 27 Wilmington 27 Mt. Olive 25 Clinton Farmer Report 34 (plus 15 in Aug) 1

2 » 2018 Raleigh 59 Wilmington Rainfall Average R Nutrient Stewardship International Plant Nutrition Institute Crop producers selecting the right product/rate/time/place combination from practices validated by research conducted by agronomic scientist. 4R Nutrient Stewardship What affects Fertility Decisions Yield Tree Health Future Production Cost Profit Aesthetics Economic Environment Social Pressures Law of the Minimum Liebig's Law Justus von Liebig, generally credited as the "father of the fertilizer industry", formulated the law of the minimum: if one crop nutrient is missing or deficient, plant growth will be poor, even if the other elements are abundant. Liebig likens the potential of a crop to a barrel with staves of unequal length. The capacity of this barrel is limited by the length of the shortest stave (in this case, phosphorus) and can only be increased by lengthening that stave. When that stave is lengthened, another one becomes the limiting factor. Right Product Match Fertilizer type to crop needs Soil Test Plant Tissue Analysis Experience Current Conditions 2

3 Does Fertilizer Source Matter? $293/acre ($9.77/tree) vs $83/acre ($2.77/tree) NCDA SOIL REPORTS TREE (FRUIT & NUT) Coastal Plain Zinc Index Questions What do I need? How Do I know? Environmental Concerns? Economic Concerns? Right Rate Match amount of fertilizer to crop needs Soil Test Plant Tissue Analysis Yield Goal/Expectation Scouting Calibration Experience FERTILIZER OPTIONS Zinc? Is soil sample Zn Index above 50? Is plant analysis above 50 ppm? Zinc is probably not necessary If needed, lbs of Zinc Sulfate foliarly during leaf expansion Use granular fertilizers containing Zinc ASSESSMENT TOOLS AVAILABLE SOIL TEST NC Dept. of Agriculture PLANT ANALYSIS NC Dept. of Ag. EXPERIENCE Potential Production 3

4 SOIL ANALYSIS SOIL & PLANT ANALYSIS BECAUSE KNOWLEDGE IS POWER SOIL TESTING At Least Every 2-3 Years Sample in Inches Routinely 8-16 Inches at Establishment Subsamples/Sample REPORT ph 5.2 N* P-I 170 K-I 28 Zn-I 76 RECOMMENDATION Lime 1.6 tons N* P - none K - 50 lbs/a Zn none What about Nitrogen Follow Soil and Plant Analysis Report for all nutrients except Nitrogen Non-bearing Trees 0.1#N/year of tree age (1# of /year) Bearing Trees 0.4#N/inch of trunk diameter (4# of /inch) TESTING SUMMARY SOIL TEST reports nutrients available from the soil PLANT ANALYSIS reports nutrients actually used 4

5 Right Time Make nutrients available when the plant needs them Application Timing Split N Product Choice Experience FERTILIZER OPTIONS How to Apply? Broadcast/tree the fertilizer in a wide band around the drip line of the tree Broadcast/acre with spreader along drip line of rows Consider split Nitrogen applications Right Place Keep nutrients where crop can use them Application Method Broadcast Broadcast Band EXPERIENCE Previous Applications AND Results 8-10 inch growth on terminal branches Site Specific Issues (soil type, leaching, etc) Production History (alternate bearing) Yield Potential Right Place ph AND LIME Neutralizes Soil Acidity Improves Nutrient Uptake ph

6 ph vs NUTRIENT AVAILABILITY NCDA SOIL REPORTS TREE (FRUIT & NUT) Coastal Plain ph Range ph and Lime Do Not Leave Money On The Table 6