MICRONUTRIENT MANAGEMENT

Amendment techniques of micro nutrient deficiency:

Amendment of Zinc deficiency in calcareous alluvial soil by natural resource management

Changing cropping system and management practices

• Zn amendment with Zn @10 kg per ha + FYM @10 t per ha was the best followed by Zn @ 10 kg per ha + FYM @5 t per ha at alternate years.
• Rice-Wheat-Sorghum is more sustainable than Rice-Mustard-Mungbean cropping system as there is more organic carbon build up in the former which varied from 0.70 to 0.77% and in latter was 0.48-0.67% in the Zn amended plots. The organic carbon build up in the control plots were 0.68 and 0.62% respectively.
• Zn use efficiency (recovery efficiency) of rice-wheat-sorghum (3.2 to 6.93%) is higher as compared to rice-mustard-mungbean (2.35 to 5.34%) cropping system in the Zn amended plots during 28 years.

Recycling of crop residues

• Initial Zn application with 10 kg ZnSO4 per ha is needed for amendment of Zn deficiency.
• In rice-wheat cropping system recycling of full crop residue after harvest of each crop can maintain available Zn content upto 20 years.
• Recycling of 50% and 25% crop residue in rice-wheat system can maintain available Zn in soil above critical level upto 11 and 4 years respectively.

Critical limits of micro and secondary nutrients in crops

The Critical concentration of nutrients in shoot at different DAS (42 to 55 DAS) was determined. Relationship between Bray’s percent dry matter yield of shoots and nutrient concentration in plant tissues was established. The critical limit varied among the varieties and crops (Zn: Rice: 21 – 27 ppm; Wheat: 42 – 52 ppm; Maize: 22 – 30 ppm); (Cu: Wheat and Barley: 7.0 – 8.8 ppm); (Fe: Rice: 44, Lentil: 74.5, Black gram: 87 ppm)(B: Black gram: 23, maize: 35, Soybean: 40 ppm).

Critical concentration of Zinc in soils

Critical concentration of Copper in soils

Critical concentration of Boron in soils