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Effects of sodium and potassium fertilisers on the composition of herbage and its acceptability to dairy cows
Author(s) -
Chiy Paul C,
AlTulihan Abdullatif A,
Hassan Mohammed H,
Phillips Clive J C
Publication year - 1998
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199802)76:2<289::aid-jsfa959>3.0.co;2-l
Subject(s) - pasture , dry matter , chemistry , zoology , sodium , grazing , potassium , agronomy , composition (language) , biology , linguistics , philosophy , organic chemistry
Fertilisation of herbage with Na can increase acceptability to cows, but the influence of fertiliser rate and fertilisation by K is unknown. In experiment 1, ten cows were grazed on pasture plots that had just been fertilised with 0–132 kg‐Na ha −1 (current Na) and had received 0–64 kg‐Na ha −1 in the previous grazing season (residual Na). Herbage Na concentration increased in proportion to current Na from 2·7 to 4·9 g‐Na kg −1 dry matter (DM) and also increased with increasing residual Na from 2·2 to 4·5 g‐Na kg −1 DM. Herbage K concentrations were low (10 g kg −1 DM at 0 kg‐Na ha −1 ) and were only slightly reduced by Na fertiliser. Herbage Mg and Ca concentrations and DM digestibility were maximum at 66–99 kg‐current‐Na ha −1 . Cows grazed current‐Na‐fertilised plots to a lower height and spent more time grazing them. In experiment 2, pasture plots received no fertiliser, low and high isomolar and independent applications of Na and K or a combination of the two. The herbage was more mature than in experiment 1 and Na concentration of the herbage without Na fertilizer was high (5 g kg −1 DM). Na fertiliser, therefore, only slightly increased Na concentration, more in clover than in grass, and had little effect on K concentration. K fertiliser increased K concentration from 16 to 20 g kg −1 DM and reduced Na concentration to 3·5 g kg −1 DM. Sodium fertiliser, therefore, only increased the acceptability of herbage to cattle when herbage Na concentrations were initially low (less than 5 g kg −1 DM) and were increased substantially by the application of the fertiliser. © 1998 SCI.