A field experiment was conducted to study the effects of partial?substitution for chemical?fertilizer?by?different organic?manure on the growth

yield

quality and nutrient use efficiency of watermelon under equivalent nutrients. Ten treatments were designed

including no fertilizer (CK)

conventional chemical fertilizer (CF)

chicken manure partial substitution for chemical fertilizer (CM)

vermicompost partial substitution for chemical fertilizer (VC) and bio-organic fertilizer partial substitution for chemical fertilizer (BOF) under fumigating with dazomet or not. Results showed that organic manure partial substitution for chemical fertilizer could improve chlorophyll content

photosynthetic performance

yield and quality of watermelon with different degrees. Compared to CF

VC could significantly enhance the leaf photosynthetic performance of watermelon

and the plants under VC were the highest in watermelon yield

soluble sugar

soluble protein

ascorbic acid

i.e. 33.63%

14.07%

14.47% and 17.52% respectively

higher than CF. The fertilizer use efficiency was improved significantly under organic manure partial substitution for chemical fertilizer. After watermelon was harvested

the fertilizer utilization efficiencies of nitrogen

phosphorus and potassium in VC treatment were 26.02%

5.67% and 29.89% respectively. On the other hand

the VC could obviously decline soil nutrient elements dependency

the dependent rate of soil nitrogen

phosphorus and potassium were 20.96%

20.32% and 31.55% respectively. And biological fumigation had an inhibiting effect on Fusarium wilt disease incidence of watermelon

the disease incidence in VC under fumigation condition was only 4.76%

which was the lowest among all treatments.