S oi,t Re s e ar c tt I n s ti t ut e, r rrf; r"o !#,fh e n t of A gr i c ut t ur e, O t t atu a Received January 8, 1965 ABSTR,A,CT In a field ex.periment.yields of barley rvere lower. rcgardless of rnoisture, when rne mean mlnrmal soll temperarure \\as near 27"C rhan lrear 9.C or lg"C. The highest yields were obtained at 18"C. Application of fertilizei increased final yields ancl uptake of N, P, and K at 9"C a,id te"C but not ar27.C. At 9"C and 18"C resp,onse to added fcrtilizer occurred as the moisturc contenr of tfte ioii was raised from rear thc u-ildng point to field capacity. During the early stages of gloYth an incrcase eitlier in temperature br moisture inireased the uptake.of N, P, and.K. Pcrce-nrage

ln the date-of-seeding trials that have been tions of 2}-25c/o with no effect from ferreported on barley, it was generally found tilizer levels (Olson and Kapusta 1960).that delayed seeding resulted in significant Woodward (1956) May,24 May,7 June and 2l June, respectively. The three moisture levels, Ml, M2, and M3 were equal to or greater than 25, 50 (normal rainfall) and,90Vo, of field capacity, respectively. The maintenance of the moisture levels has been described previously (Mack 1965

In a 3-year field experiment with bromegrass similar at all three soil temperatu-res. In grown under low m^oisture stress (( 2 itm), contrast to the effect on herbilge.yield, root iotut fr"rbug" yield from unfertiliied plois accumulation was much gre,atrlr-in the^cool *ui .i4"."? 6y 39Vo when the uveirag" soil (30J metric tons per ha, 0 to 30 cm seasonal soil temperature (14.1 C at a 50-crn depth) than in the seasonal soil (22'7 MT/ defth) was lowered and maintained at9.2 C; ha) or in-the warm soil (12.1-MT/ha). An th6 yield was increased by 71,% when the increase in concentration of the major seasonal temperature was raised and main-nutrients (N, P,-K) in the plants coincided tained at 25:4 C. This represents a change with the greater herbage growth on the warm in yielJ of 6.8% p"r i t change in tf,e soil. The-changes in lptake for N, P and K seasonal soil tempeAtuIe, or a Q,o of 7.3 at per 1 C change of, the-seasonal tempelature 9.2 C. Herbage grown on the-warm soils were 8.7, 10.4 and 1,.lVo, respe,ctlvely, and continued thro=ugh-out the season until fall. the associated Q-ro values.were 1.5, 1.6 a-nd but growth on ihe cool soils was negligible 1.4 zt 9.2 C. After growin-g lr1om-egrass for after the first har-vest in June. Addit"ioi of three years, the amount of NO"-N mineral-N, P and K to the soil in the spring reduced ized for subsequent"crops weLs low in soil itb "n". (Fig. 1) present one of the experimental parameters under which the results on growth and nutrient uptake were conducted.These moisture release characteristics were used as a basis for determining the available moisture content calculated at l/3-atm and 15-atm tensions.The moisture extraction pattern (Fig. 2) (Table 1) shows that a moisture differential was obtained between the three regimes within each temperature condition. The summary data show also that the moisture contents achieved for a particular moisture regime (e.9., M") were reasonably similar at all three soil temperatures, not only for the entire growing season but also for the mid-season extending from the first to the second harvest, when evapotranspiration would be near maximum for the year. The amounts of water required to maintain each regime under the three different temperature conditions are presented also and show the much greater amount required to maintain the moisture at a particular level when the temperature is raised.In each of the three years, 1964 to L966, daily soil temperatures (50'cm depth) in the warm plots (7") with high moisture (M") were consistently higher than in comparable cool plots (Fig. 3) For personal use only.were taken when the ;-ffi *^"'* ffi; #l.a r,.uoi,,g ""u "r::

Six clonal stocks of timothy (

Analyses were made of the amino acid com-tions of amino acids were highest at third-leaf position of rhizosphere soil of plants, grown and heading stage and lowest at the fifth-leaf in the greenhouse at two fertilily leveli and stage.