黃和炎 施宗禮 林滄澤
Long-Term Silicate Slag Application and it Extension Practice on Rice
H. Y. Huang, T. L. Shih, T. T. Lin
1. Long-term silicate slag application
This experiment has been carried out at Min-Hsung (Chia-Yi Hsin) and Hou-Pi (Tainan Hsin) since 2nd crop 1977 to 1st crop 1980 of 6 rice crops. The slag treatments were divided into 0, 1.5 and 3.0 tons per hectare by randomized block design with 2 replications, and the slag application was fixed in the same plot. The results are shown as follows: (1) The grain yield was more increased at the treatment with 3.0 ton/ha slag than with 1.5 ton/ha slag in each rice crop at Min-Hsung site, but on the contrary, the treatment of 1.5 ton/ha slag was better than the treatment of 3.0 ton/ha at Hou-Pi trial. The total silicate slag applied until 1st crop 1980 was accumulated to 9 and 18 ton/ha at the 1.5 and 3.0 ton/ha plot, respectively. However, the yield still had an 8.6% and 3.7% increase at the 3.0 and 1.5 ton/ha plot at Min-Hsung site, respectively, but 2.1% and 7.9% at Hou-Pi site. (2) The soul reaction was affected by slag application. The pH value was increased from 4.2 (at initial 3 ton/ha slag application) to 6.1 (18 ton/ha accumulation of 6 times application) at Min-Hsung filed trial, and an increase from Ph 5.2 to 6.4 at Hou-Pi field trial. (3) The available SiO2 content in soil was 11 ppm at initial (before application) and increased to 185 ppm and 98 ppm (after 6 times application) at 3.0 and 1.5 ton/ha plot, respectively at Min-Hsung field trials, but an increased from 25 ppm to 288 ppm and 132 ppm for 3.0 ton/ha plot and 1.5 ton/ha plot at Hou-Pi field trial, respectively.
2. Silicate slag extension practice
The slag extension practice work was beginning at Min-Hsung County in 1st crop 1978. The total acreage 250 hectare including ¼ of acreage applied slag and ¾ as check was carried out at each farmer’s farm. The results revealed that there was an 11.3% yield increase of average. The extension acreage was increased more than 1000 hectares until 1st crop in 1980 at hill side paddies, that got a 5.6% increase of average grain yield.
The application of slag by using a deep dressing was better than surface dressing. The optimum rate of silicate slag used was at 2 ton/ha at paddies in Chia-Nan area.