Direct and Residual Effect of Boron Application on Yield and Nutrients Content under Rice–wheat Cropping System

Aims: To investigate the direct and residual effect of boron application on yield and nutrient content under rice-wheat cropping system in middle Gangatic alluvial plan.

Study Design: Completely random design (CRD).

Place and Duration of Study: Net-house of the Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India during 2017-18.

Methodology: The pot experiment was comprised with ten treatments among them eight for boron (ranges from 0.5 to 4.0 mg B kg-1) along with control and recommended dose of fertilizer (RDF). Rice (Oryza sativa L.) variety ARIZE 6444 was used as test crop and after harvesting of rice crop, wheat (Triticum aestivum L.) variety HUW 468 was grown in the same pot without fresh application B. The yield data was recorded after harvesting of rice and wheat. The nutrient content in grain and straw and post-harvest soil properties were analyzed using standard protocol.

Results: The maximum grain yield in rice (44.07 g pot-1) was recorded in T5 (RDF + 1.5 kg B ha-1), whereas in wheat (19.70 g pot-1) was observed in T8 (RDF + 3 kg B ha-1). The maximum straw yield in rice (24.35 g pot-1) was recorded in T5 (RDF+ 1.5 kg B ka-1), whereas in wheat (48.65 g pot-1) was in T8 (RDF + 3 kg B ha-1). Application of RDF along with 1.5 kg B ha-1 was recorded the maximum (48.99%) harvest index in rice, whereas its (B) residual effect in wheat crop was maximum in RDF + 2 kg B ha-1. Application of B @ 1.5 kg B ha-1 significantly enhanced the Fe, Cu, Mn and Zn content in rice grain, whereas residual effect of 3 kg ha-1 B application has significantly improved the Fe, Cu and Mn content in wheat grain.

Conclusion: It was found that application of B did not increased grain yield of rice and wheat significantly over RDF. A significant residual effect of B application in rice was noticed even after the harvest of wheat crop particularly at highest doses of B application.