Experimental site: The long-term fertilizer trial was initiated in 1985 at the Bangladesh Rice Research Institute (BRRI), Gazipur, Bangladesh. Annual rainfall is approximately 2000 mm of which 80% is concentrated during the wet season (mid-June to end of September). The soil of the experimental field is Chhiata clay loam, a member of the fine, Hyperthermic Vertic Endaquept (Haque et al. 2015b, 2015c). Treatments, design, and fertilization The experiment was initiated in the dry season of 1985 on a permanent layout at the BRRI farm, Gazipur. Twelve treatments in a randomized complete block design (RCB design) with four replications were imposed (Haque et al. 2016, 2017). But we have considered only NPKSZn, PKSZn (-N), NKSZn (-P), NPSZn (-K), NPKZn (-S), NPKS (-Zn), and control treatments for our analyses and interpretations of findings. Since organic amendments (Cow dung, poultry manure, and vermicompost) were used from 2009 to 2017, we have taken those treatments for comparison of rice yields with chemical fertilizers. Nutrient compositions of organic materials used are shown below: In the dry season, NPKSZn @ 120–25–35–20–5 kg ha1 was used; but in the wet season (rainfed rice crop), it was 100–25–35–20–5 kg ha-1 up to 2008. After 2008, NPKSZn was used @ 138–10–80–5–5 kg ha1 and 100–10–80–5–5 kg ha-1 , for dry and wet seasons, respectively based on soil test. In dry 2009–2010, organic materials were used with þ PK, þSZn, þKSZn, þPSZn, and þ PKSZn treatments. Nitrogen (N) as urea, P as triple super phosphate, K as muriate of potash, S as gypsum and Zn as zinc chloride were used as inorganic nutrient sources. Organic nutrient sources used for selected treatments were vermicompost (VC, 2 t ha1 ), saw dust (SD, 3 t ha1 ), cow dung (CD, 3 t ha-1 ), mixed manure (CD: PM: SD: VC ¼ 1: 1: 1: 0.5), and poultry manure (PM, 2 t ha-1 ) in þ PSZn, þKSZn, þPK, and þ PKSZn treatments. Only N @ 138 kg ha-1 was applied as top dress in organic nutrient added plots. During 1985-2008, BR3 and BR11 were used as indicator crop variety in dry and wet seasons, respectively. From 2009 onward BRRI dhan29 and BRRI dhan49 were used in dry and wet seasons, respectively. Rice seedlings were transplanted in the first week of January and harvested in May for the dry season and the wet season rice was transplanted in the first week of August and harvested in the third week of November. Two to three rice seedlings (45–50 d old in the dry season and 25–35 d old in the wet season) were transplanted at 20- 20-cm spacing. Urea N was applied in three equal splits at final land preparation, active tillering stage and 5–7 d before panicle initiation (PI) stage. Rests of the fertilizers were applied at final land preparation. Rice yield and nutrient use-efficiency Grain and straw yields were determined at physiological maturity as described by Saleque et al. (2004). Grain yield was recorded at 14% moisture content (wt wt1 ), and straw weights were recorded after oven-drying at 65 C for 3 d. The apparent crop recovery efficiency (RE) of the applied nutrients was determined.