Long-term changes in yield and soil fertility in a twenty-year rice-wheat experiment in Nepal

2001 ◽  
Vol 34 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Gami S. ◽  
Ladha J. ◽  
Pathak H. ◽  
Shah M. ◽  
Pasuquin E. ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Long Term Changes

Long‐term changes in paddy soil fertility in tropical Asia after 50 years of the Green Revolution

2021 ◽  
Author(s):  
Junta Yanai ◽  
Sota Tanaka ◽  
Atsushi Nakao ◽  
Susumu S. Abe ◽  
Mina Hirose ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Paddy Soil ◽  
Green Revolution ◽  
Tropical Asia ◽  
Long Term Changes

scholarly journals Long-term changes in soil fertility in hill country

2016 ◽  
Vol 16 ◽  
pp. 157-161
Author(s):  
A.D. Mackay ◽  
D.A. Costall
Keyword(s):  
Soil Fertility ◽  
Experimental Studies ◽  
Soil Sampling ◽  
Research Station ◽  
Sheep Grazing ◽  
Hill Country ◽  
Olsen P ◽  
Long Term Changes ◽  
Total P

It has been more than 10 years since the last comprehensive soil sampling of the long term phosphorus (P) fertiliser and sheep grazing farmlet study established at the AgResearch Ballantrae Hill Country Research Station in 1975. This paper reports the findings from a sampling in October 2014 of the soils in the farmlets that have had no fertiliser since 1980 (LFNF), received 125 kg/ha/year of superphosphate since 1980 (LFLF) or 375 kg/ha/year of superphosphate since 1980 (HFHF). Increases in total P levels in the soil reflect the differences in P inputs between the LFNF, LFLF and HFHF farmlets over the last 40 years. In sharp contrast total sulphur (S) levels in soils have showed little change, despite the large amounts of sulphur applied in superphosphate each year. Exchangeable calcium (Ca) levels have increased on the farmlets receiving fertiliser, reflecting the Ca inputs in superphosphate, while magnesium (Mg) levels are lower in the HFHF farmlet. Potassium has shown little change, with the exception of increases on low slope areas in the HFHF farmlet. Olsen P levels have not changed in the topsoil (0-75 mm) in the HFHF since the 2003 sampling, despite annual P inputs in excess of maintenance. The absence of any change might be explained by the finding that P is accumulating in large amounts in the 75-150 mm soil depths on low slopes in the HFHF farmlet. This finding was unexpected serving to highlight the insights these long-term experimental studies provide to both science and industry. Keywords: Long term fertiliser study, P fertiliser, Olsen P, soil fertility

Analysis of Long-term Changes of Days with 25℃ or Higher Air Temperatures in Jeju

2016 ◽  
Vol 7 (1) ◽  
pp. 31 ◽  
Author(s):  
Jae-Won Choi ◽  
Yumi Cha ◽  
Jeoung-Yun Kim ◽  
Cheol-Hong Park
Keyword(s):  
Air Temperatures ◽  
Long Term Changes
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