Critical Limit Of Zinc In Soil

Rice soil critical limit zinc applications.

Critical limit of zinc in soil.

Among three extractants zn. The critical zn concentration in soil and plant below which plant response to zn application to the soil may be expected was 0 78 and 19 ppm respectively. Som and on organic soil s. The soil contained caco3 0 33 7 54 ph 6 2 8 8 ec 0 27 1 6 dsm 1 and organic carbon 2 7 11 4 g kg 1.

Zinc zn plays a substantial role in many biological processes and is an essential trace element for proper growth and reproduction of plants and health of animals and humans. However a substantial amount of average dry matter yield decreased with increasing levels of applied zinc fertilizer in the soils containing zn above critical limit up to 5 0 mg zn kg 1 soil. The treatments consisted 0 2 5 and 5 0 kg zn ha 1 as znso4 7h2o and recommended dose of nitrogen phosphorus and potashas urea single super phosphate and muriate of potash were used. Among three zinc extrantants dtpa hcl and ammonium acetate only dtpa zinc extractant was significant and positively correlated with bray s per cent yield and chemical properties such as ph o c and available nitrogen.

The dtpa extractable zn was positively and significantly correlated with cec organic carbon and clay contents and negatively correlated with ph silt and sand contents of soil. A pot culture experiment was conducted to determine the critical limit of zn for rice grown in veeranam command area vertisol and entisol. Critical limit of 20 mg zn g dw at high level of p application 27 mg kg 54 55. The bray s per cent yield ranged from 29 12 to 126 36 and was positively correlated with available zn r 0 93 and plant tissue zn r 0 91.

An experiment was conducted during 2016 2017 to study the critical limit of zinc in soil and plant. Critical limits of zinc in soil at harvest 0 0 20 0 40 0 60 0 80 0 100 0 120 0 50 0 52 0 54 0 56 0 58 0 60 0 62 0 64 0 66 0 zn content ppm b r a y s y i e l d fig. Introduction rice is a stable food for about 50 percent of the world s population that resides in asia where 90 per cent of the world s rice is grown and consumed. Zinc deficiency is also noticed in the soil derived from parent.

It is an important stable food that provides 66 70 per cent body. Critical limits of zinc in plant at 30 das. Pea pisumsativum l cv. The critical limit of zinc in soil and plant was found to be 0 64 and 22 0 mg kg 1 respectively.

The available zn content of soils was estimated by seven extractants and the amount of zn extracted followed the order of 0 005 m dtpa ph 7 3. Rachna was taken as the test crop.