Patel, K. P.RATHOD, DHARMSINH DIPSINH2018-07-022018-07-022003http://krishikosh.egranth.ac.in/handle/1/5810056200The present investigation was undertaken to study the comparative efficiency of different Zn-enriched organics on crop yields and increase the fertilizer use efficiency in wheat-maize (F) cropping sequence. The enrichment of different organics was carried out with Zn by composting the locally available organics viz., farm yard manure (FYM), poultry manure (PM), sewage sludge (SS) and biogas slurry (BGS) for six to seven weeks as required to complete the enrichment process. Zinc was added at 2.5 and 5.0 kg ha-1 ttirough 500 kg of organics. The enriched organics were used for field experiment on the pre-identified Zn deficient site at Forage Research Project Farm, GAU, Anand. The treatments of Zn-enriched organics were evaluated as against straight Zn application @ 2.5 kg Zn ha-1 and 5.0 kg Zn ha-1 besides control on wheat var. Lok-1 (Triticum aestivum L.)- for direct effect and on fodder maize var. GM-3 (Zea mays L.) for residual effect. The application of Zn-enriched PM and BGS to wheat in rabi was found beneficial in increasing yields of both wheat as well as maize (fodder) in summer. The Zrvenriched PM and BGS improved average wheat grain yield by about 68 and 49 per cent respectively over control whereas same was higher by 33 and 18 per cent over straight Zn application respectively. It was noticed that the grain and straw yield improvement due to 2.5 kg and 5.0 kg Zn ha-1 enrichment rates with all the organics was comparable within each organic which indicated that the Zn application to wheat could be reduced to one half of the recommended dose of 5 kg Zn ha-1 if the Zn was to be supplemented through any of the organics after its enrichment with Zn. However, Zn enrichment at higher level i.e. 5.0 kg Zn ha-1 was found beneficial with FYM as it registered total dry matter yield of wheat significantly higher by about 13 per cent over 2.5 kg Zn ha-1 Although the straight Zn application increased wheat yield significantly over control, the increase in yield was found comparatively less to that of Zn-enriched organics at both the levels of Zn application. The maize dry matter yield increased significantly due to residual effect of Zn treatments over control. The overall maximum improvement in maize dry matter due to PM and BGS was higher by about 19 and 9 per cent over straight Zn application. The residual effect was found more beneficial under PM when enriched witii Zn at 5 kg ha-1 compared to residual effect due to straight Zn application at same level. Thus, it indicated that the application of Zn-enriched FYM and PM after enrichment at 5 kg Zn ha-1 to wheat was necessary to meet the total Zn requirement in a sequence of wheat-maize (fodder) in order to get significantly higher wheat yield as a direct effect of Zn application and on succeeding maize as residual effect, respectively. The Zn application at 2.5 kg ha-1 was found sufficient when applied after enrichment with BGS and SS for higher wheat and maize yields in the sequence. The Zn-enriched PM and BGS treatments more favorably altered the nutrient contents in grain and straw of wheat than other organics over straight Zn application. The increase in grain and straw yield ultimately caused more removal of major (NPK), secondary (S) and micronutrients (Fe, Zn, Mn and Cu) by wheat due to direct effect and by maize as residual effect due to Zn treatments. The uptake of nutrients was higher under PM and BGS than FYM and SS over straight Zn application. The results further revealed that Zn-enriched PM and BGS enhanced availability of most of the nutrients especially available N, H^O, S and DTPA-extractable micronutrients like Fe and Zn after wheat. Also, the Zn-enriched PM and BGS showed beneficial effect on availability of nutrients with regard to their increase/maintenance in soil after maize due to residual effect. The efficiency of the organics was observed as PM > BGS > SS > FYM for their use after Zn enrichment in wheat-maize (F) cropping sequence. Thus, the overall findings suggested the importance and practical utility of the Zn enrichment technique for organics in integrated nutrient management to maintain fertility and crop productivity of the Zn-deficient soil.enAgricultural Chemistry and Soil ScienceA StudyThesis