Zinc (Zn) deficiency is a serious nutrient constraint to optimal rice productivity. Though zinc sulfate field application is an effective and cost-effective cure to the problem, its actual adoption remains sporadic because of genuine constraints on the part of resource-poor rice growers. Evident handicaps are the cost of zinc sulfate and its problematic uniform broadcast in puddled rice fields. Consequently, the crop keeps suffering yield losses. Therefore, NARC soil scientists conducted research for developing alternate strategies for curing Zn deficiency in the crop.
Technology Development, Demonstration and Recommendation
Multi-location, multi-year field research was undertaken in major rice growing areas of the Punjab in which a number of alternate methods of Zn augmentation were compared with the conventional method of zinc sulfate field application. This research consistently revealed that Zn-enriched rice nursery, obtained by applying a high dose of Zn to the nursery area, was comparable in effectiveness to field application of Zn. Preparing Zinc enriched nursery is much easier than field application of Zn, as zinc sulfate is broadcast applied to a much smaller piece of dry nursery area compared with much greater puddled rice field area. Also, Zn application to nursery area is 10-tiems economical compared with its field application because much lesser quantity of zinc sulfate is required per unit rice field area.
Subsequently, the technology was extensively field demonstrated in rice tract of Punjab in collaboration with Agricultural Adaptive Research. Considering its effectiveness and economy, Punjab Agriculture Department has recommended this technology to rice growers since 2003.
After preparing the nursery area, prior to applying farmyard manure and other fertilizers, Zinc Sulfate (containing 30-35% Zn) is broadcast applied – @ 30 kg Zinc Sulfate/Acre or @ 1.5 kg Zinc Sulfate/8 Marla nursery area. The rice nursery so raised contains adequate Zn to remain unaffected of soil Zn deficiency.
Rashid, A., M. A. Kausar, F. Hussain, and M. Tahir. (2000). Managing zinc deficiency in transplanted flooded rice grown in alkaline soils by nursery enrichment. Tropical Agriculture (Trinidad) 77:156–162.
Rashid, A., M. Yasin, M. Ashraf, and M. A. Kausar. (2003). Managing zinc deficiency in rice by nursery enrichment: An easy, effective and economical technology. Pakistan Agricultural Research Council, Islamabad (Urdu). 8 pp.