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Nitrate Leaching in a Udic Haploboroll as Influenced by Fertilization and Legumes
Author(s) -
Campbell C. A.,
Lafond G. P.,
Zentner R. P.,
Jame Y. W.
Publication year - 1994
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1994.00472425002300010030x
Subject(s) - leaching (pedology) , agronomy , environmental science , monoculture , crop rotation , fertilizer , soil fertility , legume , green manure , soil water , crop , biology , soil science
An ongoing 34‐yr crop rotation experiment being conducted on a heavy clay at Indian Head, SK, allowed a snap‐shot assessment to be made of the influence of fertilization, legume green manure and legume‐grass hay crops, and frequency of cropping to monoculture hard red spring wheat ( Triticum aestivum L.) on deep leaching of soil nitrate (NO 3 ). The results showed that NO 3 leaching was greatest when summer fallowing was most frequently employed. Although N fertilization may increase No 3 ‐N leached, using a soil test as a guide to choosing fertilizer application rates and cropping annually will minimize NO 3 leaching. Further, we found that, although deep‐rooted forage crops such as alfalfa ( Medicago sativa L.) remove NO 3 and water to a depth of 2.4 m, and because legumes increase the N supplying power of the soil, considerable NO 3 leaching can still occur under these systems. This is especially true if legume plowdown is followed by a fallow period, because during the fallow period, copious net N mineralization may occur together with increased soil moisture storage. These results do not imply that NO 3 leaching is pervasive on the Canadian Prairies, but they do confirm certain well‐known principles: viz., that NO 3 leaching can be expected whenever conditions favor NO 3 accumulation and water buildup in soil. Consequently, it is important to keep the land cropped for a large proportion of the time and to use fertilizers at moderate rates based on soil tests.