Comparison of Nitrate Production and Other Procedures in Determining Nitrogen Availability in Southeastern Coastal Plain Soils¹

Abstract

Synopsis Chemical methods were more closely correlated with greenhouse cropping evaluations of N availability than were the regular or modified biological incubation procedures.

Applicability of phosphate buffer extractable organic nitrogen as an indicator of available nitrogen in the sandy soils of the Sahel zone of Niger, West Africa

“…5A). A high correlation between mineralizable nitrogen in soils and nitrogen uptake by plants has been reported previously for the temperate zone (Gallagher and Bartholomew 1964; Ryan et al . 1971; Thomas et al .…”

Assessing Indices for Predicting Potential Nitrogen Mineralization in Soils under Different Management Systems

“…Gallagher and Bartholomew (1964) found that predicThree of the four indices used in this equation tions of N availability were improved when N test methods and are relatively fast to determine (<1 d) and Fl_CO2 takes only 3 d, soil properties were combined in multiple regressions. We used which is much faster than a long-term incubation.…”

“…Gallagher and Bartholomew (1964) found that predic tions of N availability were improved when N test methods and soil properties were combined in multiple regressions. Wang and Li (1991) also found that combining indices improved predic tions of plant N uptake.…”

Identification and estimation of readily mineralizable nitrogen in soils

“…Also, the value of laboratory indexes of nitrogen availability is clearly limited by the fact that the availability of soil nitrogen to plants is con trolled largely by microbial activity and by rainfall» Short periods of heavy rainfall during the growing season can lead to extensive loss of nitrate through leaching or denitrification and can completely vitiate the results of laboratory methods used to assess the need for fertilizer nitrogen. Tyurin (1934); Tyurin and Kononova (1934$ 1935)l Gracie and IChalil (1939 Gallagher and Bartholomew, 1964;Jenkinson, 1964;MacLean, 1964 Boswell et al, (1962) See Table 3 See Table 3 See Table 3 …”

“…; MacKay et al, 1959MacKay et al, , 1963; Olson et al, i960;Eagle, 19615 Gasser, 196la;Clement and Williams, 1962;Gasser and Williams, 1963;Grunes et al, 1963;Mercik, 1963;Welch and Bartholomew, 1963;Gallagher and Bartholomew, 1964; Gasser and Jephcott, 1964;Harding and Boss, 1964;Kalbande, 1964;Ozus, 1964;Stanford et al, 1965 ^î'JlîCj, water-holding capacity; ME, moisture equivalent ; R s water retained against suction after leaching with tvater; VP a used CaHPOi solution instead of water, and varied the amount from 1.5 to 3»5 mlo according to soil texture; FC S field capacity; T s amount of water retained against 75 cm* of water tension; Aer» s method of aeration: A fl by admission of fresh air at intervals during incubation; Op, by opening to air saturated with water vapor; N s not stated; Ox, oasygen absorbed during incuba tion was replaced by pure oscygen; P 5 mineral N produced during incubation was determined periodically c l" nitrate M; 2, (exchangeable ammonium + nitrate)-N; 3 ? (exchangeable ammonium + nitrate + nitrite)-!…”