Effects Of Different Calcium And Magnesium Fertilizer On The Growth,production And Quality For Tomato

Calcium and magnesium are the essential mid-elements for normal growth and development of plant. Though the irrigation water is rich in calcium and magnesium ions（calcium ions 100-140 mg/kg, magnesium ions 40-60 mg/kg） in the limestone area, there are still lack of calcium and magnesium in the production of fruit and vegetable crops. The study of suitable content of calcium and magnesium in drip irrigation fertilizer in limestone area has important theoretical and practical significance for the growth and production of tomato, the dynamic changes of calcium and magnesium in soil and the production of tomato in protected field.This experiment researches tomato cultivation in autumn and winter with a ridge and double lines cultivation mode in sunlight greenhouse at Henan Agricultural University experiment base.After planting, the test sets 4 different fertilizer cases by way of drip irrigation with the integration of water and fertilizer : case I（adding calcium, magnesium）, II（calcium）, III（magnesium） and IV（not adding calcium, magnesium）. Experiment with randomized block design is repeated 3 times. The test studies the influence of different additives of calcium and magnesium fertilizer upon growth index, production, quality of tomato, nutrient uptake of plant and physical and chemical properties of soil. The preliminary findings are as follows:（1） During the whole growth period of tomato, in terms of plant height: case IV excluding Ca²⁺ and Mg²⁺ was the best, case III including Mg²⁺ would restrain the growth of plant height; with different additives of calcium and magnesium fertilizer, the stem diameter and leaf number were also diverse, stem diameter and leaf number of case III adding Mg²⁺ were significantly higher than others. That is, the application of magnesium fertilizer reduced plant height, but it can remarkably increase the stem diameter and leaf number of tomato.（2） Influence of different additives of calcium and magnesium fertilizer on the dry and fresh material accumulation in the aerial part and underground part: in the cases of not adding Ca²⁺ and Mg²⁺, dry and fresh material accumulation in the aerial part and underground part of tomato plant were the most, the employment of calcium and magnesium fertilizer weighted against the dry and fresh material accumulation both in the aerial part and underground part of tomato plant, the accumulation of dry and fresh material of the aerial part and underground part in case III with Mg²⁺ were the minimal, which showed that the application of magnesium fertilizer would reduce the material accumulation of tomato plant.（3） Production: the fruit number for per plant of case IV without Ca²⁺ and Mg²⁺ was the maximum, the weight of per tomato of case III was the heaviest, which was 0.094 kg whereas case IV the lightest, which was 0.086 kg. Case II with Ca²⁺ was the most productive which was up to 5802.79kg/667m2. The production of case II was higher than case I, III and IV by 9.9%,7.56%and 9.2%respectively. The production of case I was 5278.17 kg/667m2 which was the minimum. It suggested that the adoption of calcium fertilizer was of great assistance for the production.（4） Quality: Vc and organic acids content in the fruit was the highest in case II with Ca²⁺, the content of soluble sugar in case I with Ca²⁺ and Mg²⁺ was the highest and the content of every ingredient was the lowest in case III with Mg²⁺. From the perspective of improving quality, adding calcium fertilizer could significantly improve Vc and organic acids content in tomato, adding Ca²⁺ and Mg²⁺ was good for the accumulation of tomato soluble sugar content but employing magnesium fertilizer would lower the quality of tomato.（5） Disease resistance: disease index of case IV excluding Ca²⁺ and Mg²⁺ was 52.08（50≤ DI<75）, which has infected disease. However, all the other three cases applying calcium and magnesium fertilizer showed certain disease resistance. The disease index of case III with Mg²⁺ was the lowest and the disease resistance effect best.（6） Nutrient absorption of N, P, K, Ca and MgAdding Ca²⁺ could significantly promote nitrogen content of stem and leaf, and increase the magnesium concent of fruit,but adding Ca²⁺ will reduce of potassium content in leaf and fruit; Adding Mg²⁺ could facilitate the absorption of potassium, and increase the absorption of calcium in root and stem, but adding Mg²⁺ inhibited the absorption of calcium in leaf and fruit. Adding Ca²⁺ and Mg²⁺ had no obvious effect on the nutrient uptake of plants.