EFFECT OF PLANT-MATERIAL PARAMETERS ON NITROGEN MINERALIZATION IN A MOLLISOL

Authors
Citation
Gc. Li et Rl. Mahler, EFFECT OF PLANT-MATERIAL PARAMETERS ON NITROGEN MINERALIZATION IN A MOLLISOL, Communications in soil science and plant analysis, 26(11-12), 1995, pp. 1905-1919
Citations number
23
Categorie Soggetti
Agriculture Soil Science","Plant Sciences","Chemistry Analytical
ISSN journal
00103624
Volume
26
Issue
11-12
Year of publication
1995
Pages
1905 - 1919
Database
ISI
SICI code
0010-3624(1995)26:11-12<1905:EOPPON>2.0.ZU;2-R
Abstract
The introduction of plant materials into a soil can impact the nitroge n (N) status and the fertilizer requirement for agronomic crop product ion. Consequently, an accurate estimate of N mineralization from soil organic matter and incorporated plant material is necessary to adequat ely make a N fertilizer recommendation. The purpose of this study was to evaluate the effect of plant parameters including type, size, incor poration rate, and time after incorporation on N mineralization and to derive localized values for parameters in a widely used potential N m ineralization model. Soil from the Ap horizon of a Latahco silt loam w as amended with alfalfa (Medicago saliva L.), spring pea (Pisum sativu m L.), and winter wheat (Triticum aestivum L.) plant materials sized t o either <1, 1 to 2, or > 2 mm at rates of 0, 2, 4, and 6%. The soils were incubated at 35 degrees C for 20 weeks. The inorganic N in soils was removed by leaching with 100 mt 0.001M CaCl2 in 5- to 10-mt interv als followed by 25 mt of a nutrient solution devoid of N (0.002M CaSO4 ; 0.002M MgSO4; 0.005M Ca(H2PO4)2; and 0.0025M K2SO4) at 0, 2,4, 6, 8, 12, 16, and 20 weeks. The main effects of plant material type (PM), s ize (S), incorporation rate (R), and incubation time (T) and many 2-, 3-, and 4-factor interactions on N mineralization were statistically s ignificant at P=0.05. Based on w(2), incubation time (T), and incorpor ation rate (R) were the two most important factors affecting N mineral ization. The amount of N mineralized increased exponentially with incr easing time and linearly with the incorporation rate. In addition, the incorporation of plant material not only increased potentially minera lizable N by as much as 5.1 times bur also accelerated N mineralizatio n in soil by increasing the N mineralization rate constant 75%.