Chemical differences between soils under farmland and under reserve vegetation were compared at nine sites on Pallic, Brown and Melanic soils (Fragiaquepts, Dystrochrepts and Haplumbrepts) in Otago and Southland, New Zealand. Farmland topsoils were more compact than topsoils of reserves, were less acid, and contained more total Al, Si, Fe, Ca, K, P and Cd. The greater content of total Al, Si, Fe and K was explained by the lower total C content and the higher bulk density of farmland soils. Higher concentrations of Ca, P, and Cd in farmland soils were explained by lime and superphosphate additions. Calcium equivalent to that contained in about 8 t/ha of lime and P equivalent to that contained in 4.5–6.5 t/ha of superphosphate have accumulated in the farmland topsoils. Farmland topsoils contained 3 to 4 times more total Cd than reserve soils because of Cd added in superphosphate, but the highest soil Cd levels were only a fraction of the maximum level recommended by the New Zealand Department of Health. Despite the ubiquitous legumes on farmland soils, farmland soils did not contain more N than reserve soils, indicating that N gain from fixation of about 140 kg ha −1 /year is probably balanced by the N loss from leaching and volatilisation. Farmland subsoils were less acid to 1 m depth, and had higher pH and exchangeable Ca and total P concentrations than reserve soils. These differences were attributed to penetration of Ca (from lime) and P (from superphosphate) into subsoils. The P increase was greatest in Brown soils, which at 0–60 cm depth had accumulated P equivalent to that contained in about 17 t/ha of single superphosphate. The study shows that reserves are valuable as soil benchmark sites, particularly for measuring the extent of pH, soil compaction and C and N change produced by farming practices, and the fate of lime, P and contaminants applied to soils.
Agriculture, Ecosystems & Environment – Elsevier
Published: Nov 3, 1997
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera