Effect of Pig Manure Compost or Sucrose Application on Recovering Chinese Cabbage from Ammonium Toxicity

Abstract

This study was carried out to evaluate the effect of application of urea and combination of urea and pig manure compost (PMC) on the occurrence of and the recovery from ammonium (NH₄ + ) toxicity in Chinese cabbage. To identify NH₄ + toxicity of the crop four levels of urea at 0, 160, 320, and 480 kg N ha -1 were applied, in addition, three levels of PMC at 10, 20, and 40 M/T ha -1 was also applied with urea 320 kg ha -1 . For recovery NH₄ + toxicity, six levels of sucrose were treated at the amount of 0, 600, 1,200, 1,800, 2,400, and 3,000 kg Cha -1 at each level of combining treatments of urea and PMC. Our results showed that NH₄ + toxicity was occurred at every urea application of 320 kg N ha -1 regardless of PMC applied to the soils because NH₄ + contents in the soils were more than 155 mg kg -1 which was found to be the critical level to damage crop growth at 2 days after transplanting (DAT) in this experiment, the more sucrose was applied up to 1,800 kg Cha -1 for the plants damaged by ammonium toxicity occurred at 320 kg N ha -1 , the greater extents recover the plants from the toxicity. PMC showed the similar effect with sucrose on recovering Chinese cabbage plants from NH₄ + toxicity at 30 DAT.