Short-term tillage practices on soil organic matter pools in a tropical Ultisol
David Sotomayor-Ramírez A D , Yusmary Espinoza B and Rafael Rámos-Santana CA Agronomy and Soils Department, College of Agricultural Sciences, University of Puerto Rico – Mayagüez Campus, PO Box 9030, Mayagüez 00681-9030, Puerto Rico.
B Centro Nacional de Investigaciones Agropecuarias – Instituto Nacional de Investigaciones Agrícolas (Ceniap-INIA); Maracay, Venezuela.
C Agronomy and Soils Dept., College of Agricultural Sciences, Agricultural Experiment Station, Corozal, Univ. of Puerto Rico – Mayagüez Campus, Puerto Rico.
D Corresponding author. Email: dsotomayor@uprm.edu
Australian Journal of Soil Research 44(7) 687-693 https://doi.org/10.1071/SR06049
Submitted: 14 April 2006 Accepted: 25 September 2006 Published: 20 October 2006
Abstract
In tropical regions, pasture establishment involves tillage operations. Adoption of conservation tillage practices could result in lower costs and in improved soil quality by decreasing soil organic carbon (SOC) losses. This study investigated the effects of 3 tillage practices on the establishment of Brachiaria decumbens and on the total SOC and soil organic nitrogen (SON) content and its fractions in an Ultisol from the humid mountain zone of Puerto Rico that was previously under pasture. The treatments evaluated were no-tillage, minimum tillage, and conventional tillage (CT). At 120 days after planting (DAP), plant cover and density was improved in the CT treatment compared with the other treatments. At 180 DAP, there were no significant differences in the SOC, SON, aggregate size distribution, distribution of C within aggregate size classes, and labile C physical fractions among tillage treatments. Approximately 60% of the total SOC associated with aggregates was found within macroaggregates. About an equal proportion of the particulate organic matter (POM) was associated within aggregates and nonaggregate-protected free light fraction, and these were not affected by tillage management. Lower amounts of C mineralised after disruption of macroaggregates containing POM with high C/N ratio was probably due to immobilisation of the more labile protected C (iPOM). Labile forms of C were greater in macroaggregates than in microaggregates, yet comprised a lower proportion of total SOC, suggesting that macroaggregates have a greater proportion of C physically protected from microbial attack. The results indicate that there are no short-term changes in the tendency of the soil to lose C and N as a result of tillage practices for the establishment of pastures in this soil.
Additional keywords: soil organic matter fractions, soil tillage practices, soil aggregates, soil organic matter protection.
Beare MH,
Cabrera ML,
Hendrix PF, Coleman DC
(1994a) Aggregate-protected and unprotected organic matter pools in conventional and no-tillage soils. Soil Science Society of America Journal 58, 787–795.
Beare MH,
Hendrix PF, Coleman DC
(1994b) Water-stable aggregates and organic matter pools in conventional and no-tillage soils. Soil Science Society of America Journal 58, 777–786.
Calderon FJ,
Jackson LE,
Scow KM, Rolston DE
(2001) Short-term dynamics of nitrogen, microbial activity, and phospholipid fatty acids after tillage. Soil Science Society of America Journal 65, 118–126.
Cambardella CA, Elliot ET
(1992) Particulate soil organic-matter changes across a grassland cultivated sequence. Soil Science Society of America Journal 56, 777–783.
Cambardella CA, Elliot ET
(1993) Carbon and nitrogen distribution in aggregates from cultivated and native grassland soils. Soil Science Society of America Journal 57, 1071–1076.
Cambardella CA, Elliott ET
(1994) Carbon and nitrogen dynamics of soil organic matter fractions from cultivated and grassland soils. Soil Science Society of America Journal 58, 123–140.
Denef K,
Six J,
Merckx R, Paustian K
(2004) Carbon sequestration in microaggregates of no-tillage soils with different clay mineralogy. Soil Science Society of America Journal 68, 1935–1944.
Elliott ET
(1986) Aggregate structure and carbon, nitrogen, and phosphorous in native and cultivated soils. Soil Science Society of America Journal 50, 627–633.
Espinoza Y
(2004) Calidad de la materia organica bajo diferentes practices de manejo en un suelo acido tropical. Revista de la Facultad de Agronomia LUZ 21, 126–140.
García-Oliva F,
Oliva M, Sveshtarova B
(2004) Effect of macroaggregates crushing on C mineralization in a tropical deciduous forest ecosystem. Plant and Soil 259, 297–305.
| Crossref | GoogleScholarGoogle Scholar |
Hassink J,
Bowman LA,
Zwart KB,
Bloem J, Brussard L
(1993) Relationships between soil textures, physical protection or organic matter, soil biota, and C and N mineralization in grassland soils. Geoderma 57, 105–128.
| Crossref | GoogleScholarGoogle Scholar |
Haynes RJ, Francis GS
(1993) Changes in microbial biomass C, soil carbohydrate composition and aggregate stability induced by growth of selected crop and forage species under field conditions. Journal of Soil Science 44, 665–675.
| Crossref | GoogleScholarGoogle Scholar |
Hernández IC,
Hernández A,
Mendoza R,
Lamorú I, Peréz V
(1990) Efecto del laboreo mínimo en el establecimiento de Panicum maximum cv. Likoni. Pastos y Forrajes 13, 157–163.
Hernández-Hernandez RM, López-Hernandez D
(2002) Microbial biomass, mineral nitrogen and carbon content in savanna soil aggregates under convencional and no-tillage. Soil Biology and Biochemistry 34, 1563–1570.
| Crossref | GoogleScholarGoogle Scholar |
Jenkinson DS
(1990) The turnover of organic carbon and nitrogen in soil. Philosophical Transactions of the Royal Society, London B329, 361–368.
Jenkinson DS, Powlson JK
(1976) The effect of biocidal treatment on metabolism in soil: V. A method for measuring soil microbial biomass. Soil Biology and Biochemistry 8, 209–213.
| Crossref | GoogleScholarGoogle Scholar |
Jenkinson DS, Rayner JH
(1977) The turnover of soil organic matter in some Rothamsted classical experiments. Soil Science 123, 298–305.
McLauchlan KK, Hobbie SE
(2004) Comparison of labile soil organic matter fractionation techniques. Soil Science Society of America Journal 68, 1616–1625.
Mikha MM, Rice CW
(2004) Tillage and manure effects on soil and aggregate-associated carbon and nitrogen. Soil Science Society of America Journal 68, 809–816.
Six J,
Elliot ET, Paustian K
(1999) Aggregate and soil organic matter dynamics under conventional and no-tillage systems. Soil Science Society of America Journal 63, 1350–1358.
Six J,
Elliot ET, Paustian K
(2000) Soil macroaggregate turnover and microaggregate formation: A mechanism for C sequestration under no-tillage agriculture. Soil Biology and Biochemistry 32, 2099–2103.
| Crossref | GoogleScholarGoogle Scholar |
Six J,
Elliot ET,
Paustian K, Doran JW
(1998) Aggregation and soil organic mater accumulation in cultivated and native grassland soils. Soil Science Society of America Journal 62, 1367–1377.
Sotomayor-Ramírez D,
Lugo-Ospina A, Rámos-Santana R
(2004) Vegetation influence on soil quality in a highly degraded tropical soil. Journal of Agriculture of the University of Puerto Rico 88, 11–26.
Tergas LE,
Vélez–Santiago J, Méndez-Cruz AV
(1988a) Production of grazed tropical grasses in different agroecosystems in Puerto Rico. III. Semiarid. Journal of Agriculture of the University of Puerto Rico 72, 211–219.
Tergas LE,
Vélez–Santiago J, Vera de Saldaña D
(1988b) Production of grazed tropical grasses in different agroecosystems in Puerto Rico. II. Humid northern coastal plains. Journal of Agriculture of the University of Puerto Rico 72, 201–210.
Tisdall JM, Oades JM
(1982) Organic matter and water stable aggregates in soils. Journal of Soil Science 33, 141–163.
| Crossref | GoogleScholarGoogle Scholar |
Wright AL, Hons FM
(2005) Soil carbon and nitrogen storage in aggregates from different tillage and crop regimes. Soil Science Society of America Journal 69, 141–147.
Yazman JA,
Vélez-Santiago J,
Arrollo-Aguilú JA, McDowell RE
(1983) Evaluation of five Tropical Grasses for growing Holstein heifers. Journal of Agriculture of the University of Puerto Rico 34, 79–94.