Ohio Water Survey During the 1998 growing season, OSU graduate student Cassandra Brown and adviser Dr. Mary Ann Rose analyzed water samples from 98 Ohio nurseries. The 132 sources used were comprised mostly of ponds and wells. The samples were collected three times: in the spring, summer and autumn, and examined for seasonal changes as well as potential water quality problems. The most common water quality problems found were high alkalinity and pH. The chart below shows findings applied to Ohio State University floricultural crop recommendations. The most "practically significant" seasonal changes observed occurred in nursery recycling pond chloride and EC. Increases from spring to summer were 0.5 mS/cm or higher for EC and/or 50 mg/L or higher for Cl for about one quarter of the recycling ponds tested. Based on the findings, growers should monitor recycling ponds throughout the growing season -- especially from spring to summer -- for increases in soluble salts. Ponds also showed increases in EC and other characteristics, but these were typically not as dramatic as for recycling ponds. Wells were consistent throughout the season in water quality; increases or decreases were rarely high enough to adversely affect production. % Samples Exceeding Recommendation Pond Recycled Well Allv wpH > 7.0 99 % 100 % 98 % 99 % Alkalinity > 120 45 % 68 % 89 % 63 % xAlkalinity > 80 81 % 89 % 98 % 87 % EC > 1.0 mS/cm 7 % 30 % 1 % 7 % yNO3-N > 5 mg/L 2 % 31% 12 % 10 % Cl > 140 mg/L 8 % 8 % 0 % 4 % SO4-S >240 mg/L 4 % 6 % 0 % 2 % yP > 5 mg/L 0 % 2 % 0 % <1 % yK > 5 mg/L 32 % 81 % 6 % 29 % Ca > 120 mg/L 8 % 23 % 4 % 8 % Mg > 24 mg/L 23 % 54 % 45 % 33 % Na > 50 mg/L 12 % 21 % 15 % 16 % SAR > 4.0 mg/L 2 % 3 % 6 % 3 % zCu > 0.2 mg/L 1 % 0 % 0 % 0 % zMo > 0.02 mg/L 2 % 0 % 2 % 1 % % Samples Not Meeting Recommendation Pond Recycled Well All SO4 < 24 mg/L 43 % 25 % 76 % 55 % Ca < 40 mg/L 22 % 4 % 10 % 18 % Mg < 6 mg/L 5 % 2 % 1 % 4 % Fe < 2.0 mg/L 100 % 100 % 100 % 100 % Al < 1.0 mg/L 98 % 100 % 100 % 99 % Mn < 0.5 mg/L 99 % 100 % 98 % 99 % Zn < 1.0 mg/L 100 % 100 % 99 % 100 % No. of samples 136 54 116 353 v All sources is comprised of ponds (30%), recycling ponds (21%), wells (35%), plus lakes, creeks and streams (8%), municipal water (4%) and springs (2%). w No samples had a pH below 5.0. Samples were collected before acid or other treatments were added. x Alkalinity below 80 mg/L is recommended for plugs. y Recommendations for NO3-N, P and K are for runoff only. Nutrients above these recommended levels will not harm plants, but may contribute to soluble salts if not considered in fertilization. z No samples exceeded the recommended levels for Fe (5.0 mg/L); Mn (2.0 mg/L); Zn (5.0 mg/L); B (0.8 mg/L); Al (5 mg/L).