Aggregation index, carbon, nitrogen, and natural abundance of 13C and 15N in soil aggregates and bulk soil cultivated with onion under crop successions and rotations
Lucas Dupont Giumbelli A , Arcângelo Loss
A F , Barbara Santos Ventura A , Elano dos Santos Junior A , Janaine Almeida A , Marisa de Cássia Piccolo B , Álvaro Luiz Mafra C , Claudinei Kurtz D , Gustavo Brunetto E and Jucinei José Comin A
+ Author Affiliations
- Author Affiliations
A Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Itacorubi, Florianopolis, SC 88034000, Brazil.
B Universidade de São Paulo, Centro de Energia Nuclear na Agricultura, Piracicaba, SP 13416970, Brazil.
C Universidade do Estado de Santa Catarina, Centro de Ciências Agroveterinárias, Lages, SC 88520000, Brazil.
D Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, Ituporanga, SC 88400000, Brasil.
E Universidade Federal de Santa Maria, Centro de Ciências Rurais, Camobi, Santa Maria, RS 97105900, Brasil.
F Corresponding author. Email: arcangelo.loss@ufsc.br
Soil Research 58(7) 622-635 https://doi.org/10.1071/SR19346
Submitted: 26 November 2019 Accepted: 17 June 2020 Published: 23 July 2020
Abstract
Use of soil cover crops of different families in crop rotation or succession under no-tillage system (NTS) for onion production results in higher soil quality compared to land use systems with less plant diversity. The objective was to evaluate the effect of using different combinations of plant species from different botanical families in rotation and succession of soil cover crops in NTS for onion production on formation of macroaggregates, mesoaggregates, and microaggregates, and on total organic C (TOC) and N (TN) contents, including isotopic forms of C and N, in soil aggregates and bulk soil. The treatments (T) evaluated were maize/onion (NTS-T1); cover plants (winter)/onion (NTS-T2); maize/winter grasses/onion (NTS-T3); velvet bean/onion (NTS-T4); millet/cover plants (winter)/onion (NTS-T5); velvet bean/rye/onion (NTS-T6); maize/onion in conventional tillage system (CTS-T7); and intercrop cover plants (summer)/onion (NTS-T8). We evaluated macroaggregates (8.0–0.25 mm), microaggregates (<0.25 mm), and bulk soil (<2.0 mm) at depths of 0–5, 5–10, and 10–20 cm, in a nine-year field experiment. The greater plant diversity in T2–T6 and T8 resulted in higher geometric mean diameter (GMD) of aggregates compared to T1 and T7. The T8 was more efficient in increasing GMD in the 10–20 cm soil depth than the other treatments. The T1 was more efficient in improving the evaluated soil physical and chemical attributes than T7. The use of NTS with plants of the Poaceae and Fabaceae families in single or intercrop systems for onion production resulted in higher TOC and TN contents in the 0–5 and 5–10 cm soil depths compared to CTS. Isotope 15N measurements showed that C and N were more protected in microaggregates in all evaluated treatments and depths compared to macroaggregates and bulk soil. Macroaggregates had more TOC and TN than microaggregates.
Additional keywords: conventional tillage system, macroaggregates and microaggregates, natural abundance of 15N, no-tillage system, onion production, soil cover plants.
References
Alves BJR, Zotarelli L, Jantalia CP, Boddey RM, Urquiaga S (2005) ‘Use of stable isotopes for the study of carbon and nitrogen in the soil-plant system. Biological processes in the soil-plant system: tools for sustainable agriculture.’ (Embrapa-SCT: Brasília)Amado TJC, Mielniczuk J, Fernandes SBV, Bayer C (1999) over crops, total nitrogen accumulation in the soil and corn yield. Revista Brasileira de Ciência do Solo 23, 679–686.
| over crops, total nitrogen accumulation in the soil and corn yield.Crossref | GoogleScholarGoogle Scholar |
Bartlett MS (1937) Properties of sufficiency and statistical tests. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences 160, 268–282.
| Properties of sufficiency and statistical tests.Crossref | GoogleScholarGoogle Scholar |
Comin JJ, Ferreira LB, Dos Santos LH, Paula Koucher L, Machado LN, dos Santos Junior E, Mafra ÁL, Kurtz C, Souza M, Brunetto G, Loss A (2018) Carbon and nitrogen contents and aggregation index of soil cultivated with onion for seven years using crop successions and rotations. Soil & Tillage Research 184, 195–202.
| Carbon and nitrogen contents and aggregation index of soil cultivated with onion for seven years using crop successions and rotations.Crossref | GoogleScholarGoogle Scholar |
Costa Junior C, Piccolo M, Camargo P, Bernoux MM, Siqueira Neto M (2011) Nitrogen and 15N natural abundance in soil aggregates in the Cerrado biome. Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde 15, 47–66.
Costa Junior C, Píccolo MDC, Siqueira Neto M, Camargo PBD, Cerri CC, Bernoux M (2012) Carbon in soil aggregates under native vegetation, pasture and agricultural systems in the Cerrado Biome. Revista Brasileira de Ciência do Solo 36, 1311–1322.
| Carbon in soil aggregates under native vegetation, pasture and agricultural systems in the Cerrado Biome.Crossref | GoogleScholarGoogle Scholar |
Coutinho FS, Loss A, Pereira MG, Rodrigues Júnior D, Torres JLR (2010) Aggregate stability and carbon distribution in Oxisol under no-tillage system, Uberaba, MG. Comunicata Scientiae 1, 100–105.
De Neve S (2017) Organic matter mineralization as a source of nitrogen. In ‘Advances in research on fertilization management of vegetable crops’. (Eds F Tei, S Nicola, P Benincasa) pp. 65–83. (Springer: Cham, Switzerland)
CQFS-RS/SC (Sociedade Brasileira de Ciência do Solo) (2004) ‘Manual de adubação e calagem para os Estados do Rio Grande do Sul e Santa Catarina.’ 10th edn. (Comissão de Química e Fertilidade do Solo: Porto Alegre, Brazil)
Del Galdo I, Six J, Peressotti A, Cotrufo MF (2003) Assessing the impact of land-use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable isotopes. Global Change Biology 9, 1204–1213.
| Assessing the impact of land-use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable isotopes.Crossref | GoogleScholarGoogle Scholar |
Empresa Brasileirade Pesquisa Agropecuária (Embrapa) (1997) ‘Centro Nacional de Pesquisa de Solos. Manual of soil analysis methods.’ 2nd edn. (Embrapa-CNPS: Rio de Janeiro)
Fabrizzi KP, Rice CW, Amado TJC, Fiorin J, Barbagelata P, Melchiori R (2009) Protection of soil organic C and N in temperate and tropical soils: effect of native and agroecosystems. Biogeochemistry 92, 129–143.
| Protection of soil organic C and N in temperate and tropical soils: effect of native and agroecosystems.Crossref | GoogleScholarGoogle Scholar |
Fernández R, Quiroga A, Zorati C, Noellemeyer E (2010) Carbon contents and respiration rates of aggregate size fractions under no-till and conventional tillage. Soil & Tillage Research 109, 103–109.
| Carbon contents and respiration rates of aggregate size fractions under no-till and conventional tillage.Crossref | GoogleScholarGoogle Scholar |
Ferreira LB, Loss A, Giumbelli LD, Ventura BS, Souza M, Mafra ÁL, Brunetto G (2018) Organic carbon and nitrogen contents and their fractions in soils with onion crops in different management systems. Soil Research 56, 846–855.
| Organic carbon and nitrogen contents and their fractions in soils with onion crops in different management systems.Crossref | GoogleScholarGoogle Scholar |
Gazolla PR, Guareschi RF, Perin A, Pereira MG, Rossi CQ (2015) Fractions of soil organic matter under pasture, tillage system and crop-livestock integration. Semina. Ciências Agrárias 36, 693–704.
| Fractions of soil organic matter under pasture, tillage system and crop-livestock integration.Crossref | GoogleScholarGoogle Scholar |
Gould IJ, Quinton JN, Weigelt A, Deyn GB, Bardgett RD (2016) Plant diversity and root traits benefit physical properties key to soil function in grasslands. Ecology Letters 19, 1140–1149.
| Plant diversity and root traits benefit physical properties key to soil function in grasslands.Crossref | GoogleScholarGoogle Scholar | 27459206PubMed |
Högberg P (1997) 15N natural abundance in soil-plant systems. New Phytologist 137, 179–203.
| 15N natural abundance in soil-plant systems.Crossref | GoogleScholarGoogle Scholar |
Hoorman JJ (2009) ‘Using cover crops to improve soil and water quality’. (Agriculture and Natural Resources, Ohio State University Extension: Lima, OH, USA)
Instituto Brasileiro de Geografia e Estatística (IBGE) (2019) Indicadores da produção pecuária. Available at ftp://ftp.ibge.gov.br/Producao_Agricola/Levantamento_Sistematico_da_Producao_Agricola_%5Bmensal%5D/Fasciculo_Indicadores_IBGE/estProdAgri_201805.pdf [verified 4 July 2020].
Jian J, Du X, Reiter MS, Stewart RD (2020) A meta-analysis of global cropland soil carbon changes due to cover cropping. Soil Biology & Biochemistry 143, 107735
| A meta-analysis of global cropland soil carbon changes due to cover cropping.Crossref | GoogleScholarGoogle Scholar |
Kihara J, Bationo A, Waswa B, Kimetu JM, Vanlauwe B, Okeyo J, Martius C (2012) Effect of reduced tillage and mineral fertilizer application on maize and soybean productivity. Experimental Agriculture 48, 159–175.
| Effect of reduced tillage and mineral fertilizer application on maize and soybean productivity.Crossref | GoogleScholarGoogle Scholar |
Ladoni M, Basir A, Robertson PG, Kravchenko AN (2016) Scaling-up: Cover crops differentially influence soil carbon in agricultural fields with diverse topography. Agriculture, Ecosystems & Environment 225, 93–103.
| Scaling-up: Cover crops differentially influence soil carbon in agricultural fields with diverse topography.Crossref | GoogleScholarGoogle Scholar |
Lange M, Eisenhauer N, Sierra CA, Bessler H, Engels C, Griffiths RI, Steinbeiss S (2015) Plant diversity increases soil microbial activity and soil carbon storage. Nature Communications 6, 6707
| Plant diversity increases soil microbial activity and soil carbon storage.Crossref | GoogleScholarGoogle Scholar | 25848862PubMed |
Li N, Yao SH, Qiao YF, Zou WX, You MY, Han XZ, Zhang B (2015) Separation of soil microbial community structure by aggregate size to a large extent under agricultural practices during early pedogenesis of a Mollisol. Applied Soil Ecology 88, 9–20.
| Separation of soil microbial community structure by aggregate size to a large extent under agricultural practices during early pedogenesis of a Mollisol.Crossref | GoogleScholarGoogle Scholar |
Li L, Vogel J, He Z, Zou X, Ruan H, Huang W, Wang J, Bianchi TS (2016) Association of soil aggregation with the distribution and quality of organic carbon in soil along an elevation gradient on Wuyi Mountain in China. PLoS One 11, e0150898
| Association of soil aggregation with the distribution and quality of organic carbon in soil along an elevation gradient on Wuyi Mountain in China.Crossref | GoogleScholarGoogle Scholar | 28030592PubMed |
Lilliefors HW (1967) On the Kolmogorov-Smirnov test for normality with mean and variance unknown. Journal of the American Statistical Association 62, 399–402.
| On the Kolmogorov-Smirnov test for normality with mean and variance unknown.Crossref | GoogleScholarGoogle Scholar |
Lima CEP, Silva JD, Guedes ÍMR, Madeira NR, Fontenelle MR (2017) Management systems effect on fertility indicators of a Ferralsol with vegetable crops, as determined by different statistical tools. Revista Brasileira de Ciência do Solo 41, e0160468
| Management systems effect on fertility indicators of a Ferralsol with vegetable crops, as determined by different statistical tools.Crossref | GoogleScholarGoogle Scholar |
Lima CEP, Silva J, Alcântara FA, Madeira NR, Carvalho AD, Fontenelle MR (2018) Effects of five years adoption of no-tillage systems for vegetables crops in soil organic matter contents. Agricultural Sciences 9, 117–128.
| Effects of five years adoption of no-tillage systems for vegetables crops in soil organic matter contents.Crossref | GoogleScholarGoogle Scholar |
Liu A, Ma BL, Bomke AA (2005) Effects of cover crops on soil aggregate stability, total organic carbon, and polysaccharides. Soil Science Society of America Journal 69, 2041–2048.
| Effects of cover crops on soil aggregate stability, total organic carbon, and polysaccharides.Crossref | GoogleScholarGoogle Scholar |
Liu Y, Liu W, Wu L, Liu C, Wang L, Chen F, Li Z (2018) Soil aggregate-associated organic carbon dynamics subjected to different types of land use: evidence from 13C natural abundance. Ecological Engineering 122, 295–302.
| Soil aggregate-associated organic carbon dynamics subjected to different types of land use: evidence from 13C natural abundance.Crossref | GoogleScholarGoogle Scholar |
Loss A, Pereira MG, Silva EM, Anjos LHC (2009a) Chemical and physical attributes of a Red-Yellow Argisol in an integrated agroecological production system. Pesquisa Agropecuária Brasileira 44, 68–75.
| Chemical and physical attributes of a Red-Yellow Argisol in an integrated agroecological production system.Crossref | GoogleScholarGoogle Scholar |
Loss A, Pereira MG, Schultz N, Anjos LHC, Silva EMR (2009b) Carbon and particle size fractions of soil organic matter under production systems. Ciência Rural 39, 1067–1072.
| Carbon and particle size fractions of soil organic matter under production systems.Crossref | GoogleScholarGoogle Scholar |
Loss A, Pereira MG, Schultz N, Anjos LD, Silva ED (2009c) Carbon and granulometric fractions of soil organic matter under organic production systems. Ciência Rural 39, 1077–1082.
Loss A, Pereira MG, Costa EM, Beutler SJ (2014) Carbon, nitrogen and the natural abundance of 13C and 15N in macro and microaggregates. Idesia 32, 15–21.
| Carbon, nitrogen and the natural abundance of 13C and 15N in macro and microaggregates.Crossref | GoogleScholarGoogle Scholar |
Loss A, Basso A, Oliveira BS, Koucher LP, Oliveira RA, Kurtz C, Lovato PE, Curmi P, Brunetto G, Comin JJ (2015) Total organic carbon and soil aggregation in an onion agroecological and conventional no-tillage system. Revista Brasileira de Ciência do Solo 39, 1212–1224.
| Total organic carbon and soil aggregation in an onion agroecological and conventional no-tillage system.Crossref | GoogleScholarGoogle Scholar |
Loss A, Pereira MG, Costa EM, Beutler SJ, Cássia Piccolo M (2016) Soil fertility, humic fractions and natural abundance of 13C and 15N in soil under different land use in Paraná State, Southern Brazil. Idesia 34, 27–38.
| Soil fertility, humic fractions and natural abundance of 13C and 15N in soil under different land use in Paraná State, Southern Brazil.Crossref | GoogleScholarGoogle Scholar |
Mendonça LA, Frischkorn H, Santiago MF, Camargo PB, Lima JOG, Mendes Filho J (2010) Identification of forest changes by 13C and 15N of Chapada do Araripe soils, Ceará. Revista Brasileira de Engenharia Agrícola e Ambiental 14, 314–319.
| Identification of forest changes by 13C and 15N of Chapada do Araripe soils, Ceará.Crossref | GoogleScholarGoogle Scholar |
Menezes Junior FOG, Kurtz C, Missio VC, Sgrott EZ, Lannes SD, Wamser GH, Werner H, Santos IA, Schmitt DR, Costa JV (Coord.) (2013) ‘Onion production system: Santa Catarina.’ 4th edn. (EPAGRI: Florianópolis, Brazil)
Miller KS, Geisseler D (2018) Temperature sensitivity of nitrogen mineralization in agricultural soils. Biology and Fertility of Soils 54, 853–860.
| Temperature sensitivity of nitrogen mineralization in agricultural soils.Crossref | GoogleScholarGoogle Scholar |
Miranda CHB, Vieira A, Cadisch G (2003) Determinação da fixação biológica de nitrogênio no amendoim forrageiro (Arachis spp.) por intermédio da abundância natural de 15N. Revista Brasileira de Zootecnia 32, 1859–1865.
| Determinação da fixação biológica de nitrogênio no amendoim forrageiro (Arachis spp.) por intermédio da abundância natural de 15N.Crossref | GoogleScholarGoogle Scholar |
Nath AJ, Lal R (2017) Effects of tillage practices and land use management on soil aggregates and soil organic carbon in the north Appalachian region, USA. Pedosphere 27, 172–176.
| Effects of tillage practices and land use management on soil aggregates and soil organic carbon in the north Appalachian region, USA.Crossref | GoogleScholarGoogle Scholar |
Pulleman MM, Six J, Van Breemen N, Jongmans AG (2005) Soil organic matter distribution and microaggregate characteristics as affected by agricultural management and earthworm activity. European Journal of Soil Science 56, 453–467.
| Soil organic matter distribution and microaggregate characteristics as affected by agricultural management and earthworm activity.Crossref | GoogleScholarGoogle Scholar |
Santos LH, Loss A, Canton L, Ventura BS, Ferreira GW, Kurtz C, Brunetto G, Lovato PE, Comin JJ (2017) Chemical properties in macroaggregates of a Humic Dystrudept cultivated with onion under no-till and conventional tillage systems. Revista Brasileira de Ciência do Solo 41, e0160419
| Chemical properties in macroaggregates of a Humic Dystrudept cultivated with onion under no-till and conventional tillage systems.Crossref | GoogleScholarGoogle Scholar |
Seben Junior GDF, Corá JE, Lal R (2016) Soil aggregation according to the dynamics of carbon and nitrogen in soil under different cultivation systems. Pesquisa Agropecuária Brasileira 51, 1652–1659.
| Soil aggregation according to the dynamics of carbon and nitrogen in soil under different cultivation systems.Crossref | GoogleScholarGoogle Scholar |
Secretária da Agricultura e da Pesca (SEAP) (2017) Maior produtor de cebola do país, Santa Catarina registra safra recorde de 630 mil toneladas. Available at: https://www.sc.gov.br/index.php/noticias/temas/agricultura-e-pesca/santa-catarina-tem-safra-recorde-de-cebola [verified 24 June 2020]
Silva JE, Lemainski J, Resck DVS (1994) Losses of organic matter and their relationship with the cation exchange capacity in soils in the cerrados region of western Bahia. Revista Brasileira de Ciência do Solo 18, 541–547.
Six J, Feller C, Denef K, Ogle SM, Sá JCM, Albrecht A (2002) Soil carbon matter, biota and aggregation in temperate and tropical soils: effects of no-tillage. Agronomie 22, 755–775.
| Soil carbon matter, biota and aggregation in temperate and tropical soils: effects of no-tillage.Crossref | GoogleScholarGoogle Scholar |
Six J, Bossuyt H, Degryze S, Denef K (2004) A history of research on the link between (micro) aggregates, soil biota, and soil organic matter dynamics. Soil & Tillage Research 79, 7–31.
| A history of research on the link between (micro) aggregates, soil biota, and soil organic matter dynamics.Crossref | GoogleScholarGoogle Scholar |
Smith BN, Epstein S (1971) Two categories of 13C/12C ratios for higher plants. Plant Physiology 47, 380–384.
| Two categories of 13C/12C ratios for higher plants.Crossref | GoogleScholarGoogle Scholar | 16657626PubMed |
Soares MDR, Campos MCC, Cunha JM, Mantovaneli BC, Oliveria IA, Brito Filho EG, Leite AFL (2018) Spatial variability of stability of aggregates and soil organic matter in archaeological black soil under pasture. Gaia Scientia 12, 125–133.
| Spatial variability of stability of aggregates and soil organic matter in archaeological black soil under pasture.Crossref | GoogleScholarGoogle Scholar |
Soil Survey Staff (2010) ‘Keys to soil taxonomy.’ 11th edn. (Natural Resources Conservation Service United States Department of Agriculture: Washington, DC)
Somasundaram J, Reeves S, Wang W, Heenan M, Dalal R (2017) Impact of 47 years of no tillage and stubble retention on soil aggregation and carbon distribution in a vertisol. Land Degradation & Development 28, 1589–1602.
| Impact of 47 years of no tillage and stubble retention on soil aggregation and carbon distribution in a vertisol.Crossref | GoogleScholarGoogle Scholar |
Souza VC, Lorenzi H (2012) ‘Systematic botany: illustrated guide for identifying families of native and exotic phanerogams in Brazil, baseado em APG III.’ 3rd edn. (Instituto Plantarum de Estudos da Flora: Nova Odessa, Brazil)
Souza M, Comin JJ, Leguizamón ES, Kurtz C, Brunetto G, Júnior VM, Ventura B, Camargo AP (2013) Matéria seca de plantas de cobertura, produção de cebola e atributos químicos do solo em sistema plantio direto agroecológico. Ciência Rural 43, 21–27.
| Matéria seca de plantas de cobertura, produção de cebola e atributos químicos do solo em sistema plantio direto agroecológico.Crossref | GoogleScholarGoogle Scholar |
Steinbeiss S, Beßler H, Engels C, Temperton VM, Buchmann N, Roscher C, Kreutziger Y, Baade J, Habekost M, Gleixner G (2008) Plant diversity positively affects short‐term soil carbon storage in experimental grasslands. Global Change Biology 14, 2937–2949.
| Plant diversity positively affects short‐term soil carbon storage in experimental grasslands.Crossref | GoogleScholarGoogle Scholar |
Szpak P (2014) Complexities of nitrogen isotope biogeochemistry in plant-soil systems: implications for the study of ancient agricultural and animal management practices. Frontiers in Plant Science 5, 288
| Complexities of nitrogen isotope biogeochemistry in plant-soil systems: implications for the study of ancient agricultural and animal management practices.Crossref | GoogleScholarGoogle Scholar | 25002865PubMed |
The Daily Records (2019) Top 13 largest onion producing countries in the world. Available at http://www.thedailyrecords.com/2018-2019-2020-2021/world-famous top–10-list/world/largest-onion-producing-countries-world-statistics-states-exporting/6564/#9_Brazil [verified 4 July 2020].
Thierfelder C, Wall PC (2010) Rotation in conservation agriculture systems of Zambia: effects on soil quality and water relations. Experimental Agriculture 46, 309–325.
| Rotation in conservation agriculture systems of Zambia: effects on soil quality and water relations.Crossref | GoogleScholarGoogle Scholar |
Tivet F, Sá JCM, Lal R, Briedis C, Borszowskei PR, Santos JB, Farias A, Eurich G, Hartman DC, Nadolny Junior M, Bouzinac S, Séguy L (2013) Aggregate C depletion by plowing and its restoration by diverse biomass-C inputs under no-till in sub-tropical and tropical regions of Brazil. Soil & Tillage Research 126, 203–218.
| Aggregate C depletion by plowing and its restoration by diverse biomass-C inputs under no-till in sub-tropical and tropical regions of Brazil.Crossref | GoogleScholarGoogle Scholar |
Torabian S, Farhangi-Abriz S, Denton MD (2019) Do tillage systems influence nitrogen fixation in legumes? A review. Soil & Tillage Research 185, 113–121.
| Do tillage systems influence nitrogen fixation in legumes? A review.Crossref | GoogleScholarGoogle Scholar |
Udom BE, Omovbude S (2019) Soil physical properties and carbon/nitrogen relationships in stable aggregates under legume and grass fallow. Acta Ecologica Sinica 39, 56–62.
| Soil physical properties and carbon/nitrogen relationships in stable aggregates under legume and grass fallow.Crossref | GoogleScholarGoogle Scholar |
Uribe N, Corzo G, Quintero M, Van Griensven A, Solomatine D (2018) Impact of conservation tillage on nitrogen and phosphorus runoff losses in a potato crop system in Fuquene watershed, Colombia. Agricultural Water Management 209, 62–72.
| Impact of conservation tillage on nitrogen and phosphorus runoff losses in a potato crop system in Fuquene watershed, Colombia.Crossref | GoogleScholarGoogle Scholar |
Vezzani FM, Mielniczuk J (2011) Aggregation and carbon stock in Argisol submitted to different agricultural management practices. Revista Brasileira de Ciência do Solo 35, 213–223.
| Aggregation and carbon stock in Argisol submitted to different agricultural management practices.Crossref | GoogleScholarGoogle Scholar |
Wang F, Weil RR (2018) The form and vertical distribution of soil nitrogen as affected by forage radish cover crop and residual side-dressed N fertilizer. Soil Science 183, 22–33.
| The form and vertical distribution of soil nitrogen as affected by forage radish cover crop and residual side-dressed N fertilizer.Crossref | GoogleScholarGoogle Scholar |
White KE, Brennan EB, Cavigelli MA, Smith RF (2020) Winter cover crops increase readily decomposable soil carbon, but compost drives total soil carbon during eight years of intensive, organic vegetable production in California. PLoS One 15, e0228677
| Winter cover crops increase readily decomposable soil carbon, but compost drives total soil carbon during eight years of intensive, organic vegetable production in California.Crossref | GoogleScholarGoogle Scholar | 32027701PubMed |
Yoder RE (1936) A direct method of aggregate analysis of soil and a study of the physical nature of erosion losses. Journal - American Society of Agronomy 28, 337–351.
| A direct method of aggregate analysis of soil and a study of the physical nature of erosion losses.Crossref | GoogleScholarGoogle Scholar |
Zhong XL, Li JT, Li XJ, Ye YC, Liu SS, Hallett PD, Ogden MR, Naveed M (2017) Physical protection by soil aggregates stabilizes soil organic carbon under simulated N deposition in a subtropical forest of China. Geoderma 285, 323–332.
| Physical protection by soil aggregates stabilizes soil organic carbon under simulated N deposition in a subtropical forest of China.Crossref | GoogleScholarGoogle Scholar |
