A field experiment was conducted at the farmers’ field of the MLT (Multi location testing) site at Joypurhat and Gabtoli, Bogura during 2015-16. The aim of the study was to verify the effect of managed bio-slurry on potato yield. There were three treatments viz. T1= Inorganic basis fertilizer dose for HYG, T2 = Cow dung bio-slurry @ 5 t ha-1+ IPNS basis inorganic fertilizer dose for HYG and T3 = Farmer’s practices. The results revealed that the yield and yield contributing characters of potato were significantly influenced by the treatments, where integrated plant nutrient management system and cow dung slurry produced a better yield of potato. In both of the locations, the highest yield and higher gross return were obtained from T2 (Cow dung bio-slurry @ 5 t ha-1+ IPNS basis inorganic fertilizer). Hence, the IPNS with bio-slurry will be a promising technology for higher crop yield and profit as well as for the improvement of soil fertility & sustain soil productivity in Joyipurhat and Gabtoli region (AEZs-25 and 4). Key words: Cowdung, bio- slurry, IPNS, Potato.
Nutrient overuse for tuber crops is particularly dramatic in some developing countries (Mueller et al., 2012). So, decreasing chemical input by balanced fertilization and nutrient management options can significantly minimize its use and subsequently, reduce GHG (Greenhouse gas) emissions (Zhang et al., 2012). Although science-based agricultural research studies have made considerable contributions to crop genetics and thus boosted both the quantity and quality of the global food supply (Wu et al., 2014), the actual yields of farmers’ fields are typically less than one-third of the potential yields found in many field studies (Mueller et al., 2012). In addition, in many regions of the world, agricultural production increases have been accompanied by a significant degradation of natural resources, including soil nutrient and organic carbon depletion. Several studies indicated that combined use of chemical fertilizer with manure could increase tuber yield and economic returns compared with fertilizer or manure alone (Rahman et al., 2011; Sarker et al., 2010). But in Bangladesh, most of the soils have less than 1.7%, and some soils have even less than 1% organic matter. The average organic matter content of top soils has declined by 20-46% over past 20 years due to intensive cropping without the inclusion of legume crops, imbalanced use of fertilizer, use of modern varieties and scanty use of organic manure (Jeptoo et al., 2013; Dada et al., 2015). It is agreed that decreases in soil fertility are a major constraint for higher crop production in Bangladesh. Application of by-product of the recently popularized biogas technology named ‘bio-slurry’ is a good source of plant nutrients and can improve soil properties (Garg et al., 2005; Asadul et al., 2015). It contains appreciable amounts of organic matter (20 to 30%) very much needed for our hungry soils. Bio-slurry provides both macro and micro-nutrients such as zinc, iron, manganese and copper that are also essential for plants but required in a trace amount to crops (Jeptoo et al., 2013). There is enough scope to work with bio-slurry linked on soil fertility and crop yield. Therefore, the present study was undertaken to evaluate the effect of bio-slurry on the yield and yield components of Potato in Joyipurhat and Gabtoli region (AEZs-25 and 4) of Banglades