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Potassium Utilization by No‐till Full‐Season and Double‐Crop Soybean
Author(s) -
Coale F. J.,
Grove H. J.
Publication year - 1991
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1991.00021962008300010045x
Subject(s) - sowing , agronomy , crop , growing season , potassium , biology , soil fertility , chemistry , soil water , ecology , organic chemistry
Although K accumulation by soybean [ Glycine max (L.) Merr.] has been studied extensively, data on differential K utilization by full‐season and double‐crop soybean are not available. Potassium utilization by no‐till soybean grown at two levels of soil K fertiliiy and two row widths was evaluated under full‐season and double‐crop planting dates. Plant component dry weight and K concentration were determined at growth stages R1, R5, and R7. For both planting dates, high soil K fertility resulted in elevated tissue K concentration and K accumulation in all plant parts at all three growth stages. At R1, double‐crop soybean tissue K concentrations were greater than that of full‐season soybean. At R7, double‐crop soybean leaf and abscised tissue K concentrations were lower than those of full‐season soybean, suggesting a disproportionately greater translocation of K out of the double‐crop soybean leaf during seed‐fill. At R7, seed K accounted for 64 and 38% of total plant K for low and high K fertilily regimes, respectively. seed IC at R7 was a constant proportion of total K accumulated for both full‐season and double‐crop planting dates. Row spacing did not alter shoot K concentration or accumulation for either planting date. Potassium accumulation rate was greatest between R1 and R5, was increased by high K fertility conditions, and was not different between full‐season and double‐crop planting dates except during the seed‐filling period when the fullseason soybean K uptake rate was greater. Full‐season soybean maintained a greater soil K uptake rate during seed‐fill while double‐crop soybean seed K supply was apparently more dependent on redistribution of K from other plant tissues.