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.
Critical limit of zinc in soil.
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.
Zinc deficiency is also noticed in the soil derived from parent.
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.
Pea pisumsativum l cv.
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.
A pot culture experiment was conducted to determine the critical limit of zn for rice grown in veeranam command area vertisol and entisol.
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.
The critical limit of zinc in soil and plant was found to be 0 64 and 22 0 mg kg 1 respectively.
Rachna was taken as the test crop.
Among three extractants zn.
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.
A study was conducted in 22 alluvial soils of west bengal india to estimate the critical limit of zn in soil and rice plant for predicting the response of rice oryza sativa to zinc application.
Soil z n ppm critical limits of zn in soil fig.
Critical limit of 20 mg zn g dw at high level of p application 27 mg kg 54 55.
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.
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.
It is an important stable food that provides 66 70 per cent body.
Critical limits of zinc in plant at 30 das.
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.
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.
It has also been reported to cause contamination of soil water and food chains in human beings zn deficiency is associated to diet quality exacerbated by zn deficient soils 4 5.
Rice soil critical limit zinc applications.
