A lysimeter investigation of nitrogen gains and losses under various systems of covercropping and fertilization, and a discussion of error sources

Abstract

There is an enormous amount of literature concerning various phases of the nitrogen problem. Most of the work reported, however, has been carried out under cropping, management, fertilization, soil, and climatic conditions foreign to those common to this region, and hence has little or no local value. Only such work, therefore, as shows the general trend of findings elsewhere is reviewed here.Relative to unaccounted-for losses of nitrogen, there is evidence that under some conditions considerable nitrogen escapes to the atmosphere. Russel (1921)6 reports that on one of the Broadbalk wheat plots receiving 14 tons of farmyard manure per acre annually, nearly 70 per cent of the nitrogen was unaccounted for and presumably disappeared into the air by gaseous volatilization. In the first five years of a study with a group of California soils in galvanized-iron tanks, Burd and Martin (1931) reported unaccounted-for losses of nitrogen averaging about 100 pounds per acre per year from both cropped and uncropped soils.Lipman and Blair (1921), working in New Jersey, obtained evidence of unexplained losses of nitrogen from a loam soil, amounting to 1,000 pounds in a ten-year period. In lysimeter experiments on New York soils, Bizzell (1944) reports unaccounted-for losses of nitrogen under cropping systems of continuous timothy, as well as in rotations of corn, oats, and timothy, ranging from 289 to 436 pounds of nitrogen per acre for a twelve-year period. In another fifteen-year lysimeter experiment reported by Lyon and Bizzell (1927), the nitrogen loss unaccounted for by crop removal and drainage amounted to 25 pounds per acre per year. In lysimeter experiments at the New York State Agricultural Experiment Station, Collison, Beattie, and Harlan (1933) reported losses ranging from 11 to more than 80 pounds per acre per year.In a study of nitrogen and organic-matter losses of Utah soils, Bracken and Greaves (1941) noted that amounts of nitrogen considerably in excess of those removed by crops were lost from the soil. They think that leaching or erosion accounts for but a small amount of this loss, and suggest that chemical or biological changes promote the volatilization of nitrogen.

Stimulation of Native Annual Clovers through Application of Sulfur on California Foothill Range

“…The need for additional soil nitrogen to increase grass production has been indicated by responses to nitrogen fertilizer on all sites at the Experimental Range. This nitrogen deficiency is typical of foothill soils and has been reported on other areas (Dickey, et al, 1948;Chapman, et al, 1949). Response to added nitrogen has been impressive and consistent on some fairly deep, heavy soils and a program of nitrogen fertilization has been recommended for some foothill areas (Hoglund, et al, 1952).…”

Rapid N^2 Fixation in Pines, Alder, and Locust: Evidence From the Sandbox Ecosystems Study

“…Modem ecosys- Ecology,Vol. 74,No.2 tern experiments and comparisons have repeatedly noted a rapid accumulation of N in a variety of ecosystems containing symbiotic N 2 fixers (e.g., Chapman et al 1949, Tarrant and Miller 1963, Van Cleve et al 1971, Cromack et al 1979. At the same time, rapid N 2 fixation in symbiotic N 2 fixers is suggested by direct measures of nitrogenase activity extrapolated to an area and yearly basis (e.g., Binkley et al 1982, Bormann andGordon 1984).…”

Nitrogen fixation in latosolic soil under grass

“…The nitrogen status of the soil may influence fixation as was recognized by Chapman et al 9 when they stated that from an agricultural point of view "greatest nitrogen economy will be achieved where available nitrogen is maintained at the lowest possible point consistent with satisfactory crop performances". In the present experiment nitrogen fixation in the grass--soil systems occurred when the initial soil nitrogen levels were low (0.05 per cent) but not when they were somewhat higher (0.07 and 0.09 per cent).…”

“…The use of lysimeters eliminates most of the errors possible in conventional Iield experiments on nitrogen economy and gains of nitrogen have still been found under these circumstances, e.g. C h a p m a n et al 9 reported gains of 40 pounds of nitrogen per acre per year under mustard, S m i t h 25 22 pounds per acre per year under wheat, and G e l ' t s e r 11 from 45 to 66 kg per hectare per year under perennial grasses and irises. In addition there would appear to be some doubt as to the validity of using "efficiency" values determined in pure culture in the laboratory to calculate the possible magnitude of non-symbiotic nitrogen fixation in a medium as complex as soil, particularly since theoretical thermodynamic considerations indicate that the reduction of nitrogen gas to ammonia by glucose would be an exothermic reaction 2.…”