Updated Fertilization Recommendations for Drip Irrigated Crops

Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu

Extension specialists in the Mid-Atlantic have updated fertilizer recommendations for drip irrigated plasticulture production of crops in the Commercial Vegetable Production Recommendations. The following are recommendations for watermelons and tomatoes.

Suggested Fertilizer Program Using Trickle Irrigation for Watermelons

Days After Planting	Daily		Cumulative
	Nitrogen¹	Potash^1,2	Nitrogen¹	Potash^1,2
	——————–lbs/A——————–
Preplant³	—	—	25	50
0-14	1.0	1.0	39	64
15-28	1.5	1.5	60	85
29-56	2.0	2.0	116	141
57-78	1.5	1.5	137	166
79-93	1.0	1.0	150	175

¹Adjust rates accordingly if you apply more or less preplant nitrogen and potash.
²Base overall application rate on soil test recommendations.
³Applied under plastic mulch to effective bed area using modified broadcast method. Adjust as needed.
Note: recommendations are based on 8 foot bed centers. If beds are narrower, fertilizer rates per acre should be adjusted proportionally. Drive rows should not be used in acreage calculations.

Suggested Fertigation Schedule – Fresh Market Tomatoes

Days After Planting	Daily		Cumulative
	Nitrogen¹	Potash^1,2	Nitrogen¹	Potash^1,2
	——————–lbs/A——————–
Preplant³	—	—	50	125
0-14	0.5	0.5	57	132
15-28	0.7	0.7	67	142
29-42	1.0	1.0	81	156
43-56	1.5	1.5	102	177
57-77	2.2	2.2	148	223
78-98	2.5	2.5	201	276

¹Adjust rates accordingly if you apply more or less preplant nitrogen and potash.
²Base overall application rate on soil test recommendations.
³Applied under plastic mulch to effective bed area using modified broadcast method. Adjust as needed.
Note: recommendations are based on 6 foot bed centers. If beds are narrower, fertilizer rates per acre should be adjusted proportionally. Drive rows should not be used in acreage calculations.

Additional recommendations can be found in the Recommendation which is also online at this site: http://ag.udel.edu/extension/vegprogram/publications.htm.