Effects of Mixed Application of Ethylenediamine-N,N'-disuccinic Acid and Fertilizer on the Growth of Watermelon and Soil Properties of Plastic Film House

Chelating agents enhance the availability of cationic nutrient by mobilizing salts in the soil. This study was conducted in the field to evaluate the effects of Ethylenediamine-N,N'-disuccinic acid (EDDS) as chelating agent and fertilizer application on improving plant growth and changing soil properties of plastic film house. The treatments were conventional application practice (NPKC), fertilizer application by soil testing (soil testing), EDDS plus 10% (EDDS+NPKC 10%), 25% (EDDS+NPKC 25%), and 50% (EDDS+NPKC 50%) of conventional fertilizer application level. Soil electrical conductivity, nitrate nitrogen, and exchangeable potassium of EDDS+NPKC 25% treatment decreased compared to those of NPK treatment, but the enzyme activity of microbial community increased. The amount of N, P, K, Ca, Mg and Fe uptaken by plant tended to be high compared to those of NPK treatment. These results showed that mixed application of EDDS and a quarter of conventional fertilizer could improve the watermelon growth and reduced the soil salinity.Soil chemical properties after harvest of watermelon in soil treated by EDDS. Treatment pH (1:5 H2O) EC (dS m-1) NO3-N (mg kg-1) Av. P2O5 (mg kg-1) Exch. cations (cmolc kg-1) K Ca Mg NPKC 6.1 a† 7.27 a 460 a 582 b 1.2 a 9.6 b 3.6 b Soil testing 6.0 a 5.30 ab 216 b 498 c 0.9 ab 9.6 ab 3.4 bc EDDS+NPKC 10% 6.2 a 4.07 b 118 b 482 c 1.1 ab 11.0 a 4.3 a EDDS+NPKC 25% 6.3 a 4.36 b 172 b 543 bc 0.8 b 9.4 b 3.2 bc EDDS+NPKC 50% 6.2 a 4.77 b 209 b 689 a 1.1 ab 9.2 b 3.0 c †Duncan’s multiple range test (p < 0.05).