24% yield increase in green pepper with Polysulphate application.
Location
Hainan, China
Objective
To investigate the effect of increasing rates of Polysulphate on the soil pH after harvest, yield and shelf life of green pepper.
Treatments
This randomized block trial consisted of three replicates with five treatments. In all treatments, nitrogen, phosphorus and potassium were applied according to farmers’ traditional practice: 1,125 kg/ha of compound fertilizer (15-15-15) applied as base-fertilizer followed by a topdressing of 375 kg/ha of compound fertilizer at fruit stage. Four treatments consisted of increasing rates of Polysulphate: 375, 750, 1,125 and 1,500 kg/ha. Control treatment received the same NPK but no Polysulphate was applied.
Results
- Application of Polysulphate increased the pH after harvest and thus the availability of nutrients in the soil, especially for K, Ca and Mg, that in turn improves the fertility of acidic soil.
- There was no significant difference in the percentage of marketable pepper among all treatments after 9 days of storage. As the storage time was increased from 9 days to 15 and then 20 days, a significantly higher percentage of marketable pepper was achieved in treatments that contained Polysulphate, due to improved shelf life.
- Comparing Polysulphate treatments with the control, the yields of green pepper increased significantly by up to 24% at the highest dose (1,500 kg Polysulphate/ha).
- Polysulphate application was very profitable, with increasing additional profits of 960, 1,620, 2,415 and 2,250 USD/ha for 375, 750, 1,125 and 1,500 kg Polysulphate/ha respectively when compared with the control treatment.
