<![CDATA[Non-organic agriculture has succeeded in increasing the production of lowland rice, but on the other hand also has a negative impact on the ecosystem of agriculture and the environment, such as the decreasing content of soil organic matter. One effort that can be done, is by adding bio-slurry organic fertilizer to the NPK fertilizer. This study was conducted to determine the effect of the combination of bio-slurry fertilizer and NPK fertilizer on the production of four rice paddy varieties. This research by experiment was conducted in Screen House Agrotechnopark, Faculty of Animal Husbandry and Agriculture, Diponegoro University, Tembalang Semarang campus, taking place from October 2018 to January 2019. The experiment used a randomized completely block design with two factors and three replications. The first factor was a combination of bio-slurry + NPK fertilizer ie without N (P0) fertilizer, NPK 550 kg ha-1 fertilizer (P1), bio-slurry fertilizer 3 tons ha-1 + NPK fertilizer 400 kg ha-1 , 6 tons ha-1 bio-slurry fertilizer + 250 kg ha-1 NPK fertilizer, 9 tons ha-1 bio-slurry fertilizer + 100 kg ha-1 NPK fertilizer and 12 tons bio-slurry fertilizer ha-1. Whereas the second factor was the lowland rice varieties namely Inpari 23, Sultan Unsrat, Sintanur and Gilirang. The results of the variance analysis showed that the combination of bio-slurry + NPK fertilizer and lowland rice varieties had a very significant effect on grain yield per clump, number of filled grains, number of empty grains, total grain count, weight of 1000 grains, rice yield per pot and harvest index. The highest grain yield per clump (85.33 g) was obtained from the treatment of 550 kg ha-1 NPK fertilizer, while the highest grain yield per clump (58.06 g) was obtained from the Gilirang variety (V4), the highest total grain amount (174.58 grains) was obtained from the treatment of NPK 550 kg ha-1 and (212.28 grains) fertilizer produced by varieties Inpari 23. The highest yield per pot of rice (61.83 g) was obtained from the treatment of 550 kg ha-1 NPK fertilizer , while the highest paddy rice varieties which produced rice per pot of (63.22 g) were Inpari 23.]]>
