de Almeida Moreira, Fernando

Godoy, Rodolfo

Menezes Santos, Patrícia

Santos Bacchi, Osny Oliveira

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Selection of Forage Pigeon‐Pea (Cajanus cajan (L.) Millsp) Lines for Soil Decompaction Rodolfo Godoy EMBRAPA, Brazil Osny Oliveira Santos Bacchi Universidade de São Paulo, Brazil Patrícia Menezes Santos EMBRAPA, Brazil Fernando de Almeida Moreira Unipasto, Brazil Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/2-1/10 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　 瞯 ]305　 瞯Grasslands/Rangelands Resources and Ecology ——— Soil Quality and Plant NutritionSelection of forage pigeon‐pea (Cajanus caj an (L .) Millsp) lines for soil decompactionRodol f o Godoy 1 , Osny Oliveira Santos Bacchi2 , Patrícia Menezes Santos1 and Fernando de A lmeida Moreira31 Embrapa Pecu被ria Sudeste , Caixa Postal 339 , 13560‐970‐S本o Carlos‐SP , Braz il . E‐mail :godoy＠ cp pse .embrapa .br ,2 Centro de Energia Nuclear na A gricultura‐CENA /USP , Caixa Postal 96 , 13400‐970‐Piracicaba , SP , Braz il . E‐mail :osny＠ cena .usp .br3 Unipasto‐STN‐K‐Sala 11‐Ed . Montreal I I‐70770‐100‐Brasí lia , DF , Braz il , E‐mail : unip asto＠ unip asto .com .brKey words : Caj anus caj an , soil compactation , decompactationIntroduction According to Camargo & Alleoni ( １９９７ ) , pigeon‐pea plays an important role among species fit to promote soildecompaction , due to the capacity of its roots to penetrate highly compacted soil layers . Since differences not only amongspecies but also within species have been observed for this character , selection within a species like Caj anus caj an seems to bean excellent aid to help solving the problem of soil compaction . This work had the purpose of selecting , among forty pigeon peapure lines , the most efficient genotypes to promote soil decompaction .Materials and methods In a series of five experiments , seeds of forty pure forage pigeon‐pea lines were planted in PVC tubescontaining an upper ３０ mm layer of vermiculite , compacted clayey soil ( to a density of １ .６ g / cm３ ) and a lower vermiculitelayer , in a randomized block design with four replications , in a greenhouse . Nine pre germinated seeds were planted in each １４３mm diameter tube . Around two weeks af ter planting , the plants were harvested and dry mass of their parts was determined . Inall experiments , the cultivar Fava Larga served as the control and the main measured characteristic was the amount of rootsproduced in the compacted soil layer . Three lines were selected and went though a series of three experiments where , besidespigeon‐pea root and shoot dry mass , root development of Tanz nia grass plants ( Panicum max imum Jacq .) seeded af ter pigeon‐pea harvest was evaluated . The experiments had ten blocks , half of which had the pigeon‐pea plants completely harvested afterapproximately two weeks . In the other half , the aerial part of the pigeon‐pea plants was removed ; Tanz nia seeds were plantedand after about two weeks the plants were harvested and the same type of data were collected . Sample compacted blocks wentthrough computerized tomography to check their soil bulk density uniformity .Results In the series of five experiments , three lines were selected since they yielded significantly more roots in the compactedsoil blocks : g５ ～ ９４ , g８ ～ ９５ and g１２４ ～ ９５ , although high variation coefficients were found . These lines went trough newexperiments : in the first one , sand was used in the place of the upper vermiculite and that caused , due to water infiltration , soilpenetration resistance to fall from ３ .８ MPa to １ .６ MPa , in two weeks . For that reason , the second part was not performed andTanz备nia grass seeds were not planted . Also in this case , g５ ～ ９４ had significantly higher amount of roots in the compactedlayer than the control . A second experiment was performed , using again vermiculite in the upper layer . When the pigeon‐peaplants were harvested , average penetration resistance of the soil blocks was １４ .６ MPa and the tubes that had received the FavaLarga plants had significantly ( Duncan p ＜ ０ .０５ ) higher resistance than those that received the g８ ～ ９５ plants . Dunnett test( p ＜ ０ .０５ ) revealed superiority of g５ ～ ９４ and g８ ～ ９５ over the control , in quantity of roots in the compact layer , but nodifference was found among the Tanz备nia plants , when the variation coefficient went up to ４９％ . In the third experiment , thesame scheme was performed but only the g５ ～ ９４ and g８ ～ ９５ lines were used . When the pigeon‐pea plants were harvested theaverage penetration resistance was １２ .６ MPa and the variation coefficient , ２０ .７ ％ . When the Tanz备nia plants were harvested ,penetration resistance ranged from １ .７ to ２４ .８ MPa and the variation coefficient was ６８ .５％ , demonstrating that the longerstaying of the plants in the greenhouse tends to cause problems in the soil properties , confirming observations by De Maria(１９９９ ) about problems to evaluate roots under these conditions . Root dry mass of the two lines were significantly higher thanthat of the control ( Dunnett p ＜ ０ .０５ ) . Roots of the Tanz备nia grass grown where those lines had been grown were onlynumerically higher than those of the control , probably due to the high variation coefficients . Tomographical images revealedthat the blocks were uniformly compacted and horizontallly the soil bulk densities ranged from １ .４１ to １ .５２ g / cm３ .Conclusions There is genetic variability in the Caj anus caj an species to penetrate compacted soil layers and two genotypes , g５ ～９４ and g８ ～ ９５ were the most efficient . The artificially compacted soil blocks used were adequate for the purpose of theseexperiments , since tomographical images revealed their soil bulk density uniformity .ReferencesCamargo , OC . , ALLEONI , LRF (１９９７) Compacta毕本o do solo e o desenvolvimento das plantas . Piracicaba . １３２ p .De Maria IC , Castro OM , Souza Dias H (１９９９) Atributos fí sicos do solo e crescimento radicular de soja em latossolo roxo sobdiferentes métodos de preparo do solo . Rev ista Brasileira de Ci崩ncia do Solo , ２３ , ７０３‐７０９ .

Selection of Forage Pigeon‐Pea (\u3cem\u3eCajanus cajan\u3c/em\u3e (L.) Millsp) Lines for Soil Decompaction

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=2472&amp;context=igc

Selection of Forage Pigeon‐Pea (\u3cem\u3eCajanus cajan\u3c/em\u3e (L.) Millsp) Lines for Soil Decompaction

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