Yield of Bromegrass and Removal of Nitrogen, Phosphorus and Potassium Under Modified Soil-Temperature Field Conditions

Abstract

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::

Soil Temperature and Moisture Conditions in Relation to the Growth and Quality of Field Peas

“…The increased concentration of P in the vine and grain associated with high soil temperature coincides with results previously reported for bromegrass (Mack 1971) and soybeans (Mack and Ivarson 1972 …”

“…La teneur en P des parties a6riennes a augment6, en g6n6ral, en fonction de la temp6rature et de optimum (e.g., at Vancouver, British Columbia) the mean maximun temperature was positively corrclatecl with vine and pea yleld (Fletcher et al 1966 (Mack 1971 The cooking quality of peas was evaluated on selected whole peas. Fifteen g of the seed were placed in 75 ml of cold water, brought to a boil, cooked for a 2-h period, and the puree was poured into a petri dish as described by Halstead and Gfeller (1964 (Mack 1971).…”

“…Fifteen g of the seed were placed in 75 ml of cold water, brought to a boil, cooked for a 2-h period, and the puree was poured into a petri dish as described by Halstead and Gfeller (1964 (Mack 1971). For personal use only.…”