HI
Soils and Soil Preparation - Well drained soils are a must for successful production, and very sandy soils are preferred. Good drainage is important in control for crown rot disease of asparagus. Commercial plantings of asparagus should not be made in soil that is heavier than a sandy loam. Avoid sites which retain standing water for more than 8 hours after a heavy rain.
Soil pH should be in the 6.2 to 6.8 range. Test soil the first year and then every other year. Lime according to soil test results. Apply lime the first year by spreading it on the surface and moldboard plowing the field to a minimum of 10 inches. Plowing will incorporate the lime to the deeper levels where it is needed. Do not disk or harrow the lime before plowing, so that it can be incorporated through the plowed layer. Lime should be applied as early as possible and preferably 6 months before planting time. Lime should be applied every other year.
Phosphorus is important to root growth and especially during establishment. Phosphors fertilizer is needed only at planting. The soil test will indicate how much phosphorus is needed. In addition, band 20 pounds of phosphate per acre as super phosphate treble super phosphate. After the first year, asparagus will recycle the phosphorus and no additional is needed.
Preplant application of nitrogen and potassium will depend on the soil test. Generally 75 to 100 pounds per acre of nitrogen and 150 to 250 pounds per acre of potassium is needed for most North Carolina soils. Spread the fertilizer for the first year on top of the soil and plow in the same as for lime.
Irrigation - Adequate moisture should be maintained for good germination and early seedling growth. Do not let asparagus plants become dry while they are establishing a root system during the first two months. Water stress during this early stage can reduce yields during life of the bed. After the root system is established, irrigation is needed only during extreme drought.
Direct Seeding Methods - Precision seeders such as a Stanhay, Gasparado, Nibex, or John Deere 33 which precisely space single seed are best. Seeds should be placed 2 inches apart in the row, 3/4 to 1 inch deep. Single row seedings require 2 to 3 pounds of seed per acre and double rowseedings require 4 to 6 pounds per acre. Asparagus seedsgerminate best at 75°F.
Harvesting - Asparagus can be harvested on limited basis (2 to 3 weeks, or 8 spears per plant) during the first year after planting. Harvesting should be limited during the second year; watch for slight reduction in spear size as an indication of when to stop. It takes a long time for asparagus to develop a large root system. A large root system is necessary for a healthy bed of asparagus to produce for many years. Do not harvest too much in early years because bed life can be shortened and total yield and profit drastically reduced. Harvest 6 to 8 weeks during the third year of growth. This is generally until mid-May in the east and mid-June in western North Carolina. Allow spears to reach 8 inches tall and then cut with a knife or hand snap at the soil surface. Spears should not be allowed to get taller than 9 inches. The decision on when to harvest is based on having an average of one harvestable size spear per foot of row. When temperature exceeds 80°F it may be necessary to harvest daily.
REgards
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