Tolerance of Wheat to Soil Sodicity Can Be Better Detected through an Incremental Crop Tolerance Approach and Ascertained through Multiple Sowing Times

Soil sodicity is a significant crop production constraint around the world. Inherited tolerance is a precursor to pre-breeding and breeding tolerant cultivars. However, high yield per se and seasonal variability are potential limitations to identify real tolerance rather than escape correctly. To minimise this risk, we generated yield, yield components and supporting data at two times of sowing (TOS) of 15 lines representing four quadrants of a biplot from a sodic- vs. non-sodic yield dataset of 112 wheat lines trialled in the previous year. Data from sodic and non-sodic sites were investigated using three analytical approaches namely, simple ratio of yield (REI), ratio of genotypic effects (TI) after excluding site effects, and the incremental crop tolerance (ICT) reflected as deviation from regression. REI and TI produced similar results showing ninelines to be tolerant, but only four lines namely, Scepter, Condo, WA345, and WA134 passed the ICT test. The tolerance comparison at the two TOSs differentiated lines tolerant at either or both TOSs. Association of Yield-ICT with leaf tissue mineral analysis and ICT for morphological traits was genotype specific, thus not usable invariably for detection of tolerant germplasm. Hence, we conclude that (i) focussing on yield rather than yield components or tissue tests, (ii) following the ICT approach, and (iii) evaluation at multiple sowing times will provide an accurate and rigorous test for identifying inherited tolerance that breeders and physiologists can reliably use. We anticipate our suggested approach to be applicable globally across crops.

EFEITO TEMPORAL DA UTILIZAÇÃO DE BIOSSÓLIDO E EFLUENTE TRATADO NA SODICIDADE E SALINIDADE DO SOLO

EFEITO TEMPORAL DA UTILIZAÇÃO DE BIOSSÓLIDO E EFLUENTE TRATADO NA SODICIDADE E SALINIDADE DO SOLO DÁVILLA ALESSANDRA DA SILVA ALVES1; RAFAEL OLIVEIRA DE MELO2; JÉSSICA DE LIMA3; JOSÉ CARLOS COELHO4 E HÉLIO GRASSI FILHO5 1Doutoranda em Agronomia: Irrigação e drenagem, Faculdade de Ciências Agronômicas (FCA/UNESP), Rua José Barbosa de Barros, 1780, CEP 18610-307, Jardim Paraíso, Botucatu/SP, Brasil. e-mail: [email protected]; 2Engº Agrº, Grupo MNS, Avenida Miguel Petrere, N° 777, Pilar do Sul/S, CEP: 18185-000. Contato: (015) 3278-9000, Sorocaba/SP, Brasil.. e-mail: [email protected] 3Mestre em Agronomia: Irrigação e drenagem, Faculdade de Ciências Agronômicas (FCA/UNESP), Rua José Barbosa de Barros, 1780, CEP 18610-307, Jardim Paraíso, Botucatu/SP, Brasil. e-mail: [email protected] 4Mestre em Agronomia: Irrigação e drenagem, Faculdade de Ciências Agronômicas (FCA/UNESP), Rua José Barbosa de Barros, 1780, CEP 18610-307, Jardim Paraíso,Botucatu/SP, Brasil.. e-mail:[email protected] 5Prof. Dr. Depto de Solos e Recursos Ambientais, Faculdade de Ciências Agronômicas (FCA/UNESP), Rua José Barbosa de Barros, 1780, CEP 18610-307, Jardim Paraíso, Botucatu/SP, Brasil. e-mail: [email protected] 1 RESUMO Objetivou-se avaliar o efeito do uso contínuo de doses de biossólido e efluente doméstico tratado no potencial de risco de sodicidade e salinidade do solo. O delineamento experimental foi inteiramente casualizado em parcelas subdivididas com dez tratamentos e cinco repetições. As parcelas consistiram no uso de dois tipos de água para irrigação (AR- efluente doméstico tratado e AB- água de abastecimento) e as subparcelas pelas doses de biossólido (0, 50, 100, 150 e 200 %), nos anos de 2011 a 2016. Avaliaram-se a condutividade elétrica (CE), pH, Ca, Mg, Na, RAS e PST do solo. Conclui-se que o efeito da adubação mineral (0% - controle) com AB foi semelhante ao uso do efluente na CE do solo para o mesmo tratamento. Doses a partir de 127,4% e 113,2% de biossólido, respectivamente, junto a AR e AB diminuíram o teor de Na+ trocável do solo. Os resultados indicaram baixo risco de sodicidade e salinidade, após cinco anos de uso. Palavras-chave: condutividade elétrica, sódio, reuso ALVES, D.A.S, DE MELO, R. O., DE LIMA, J., COELHO, J.C., GRASSI FILHO, H TEMPORAL EFFECT OF CONTINUOUS USE OF BIOSOLID AND EFFLUENT TREATED IN THE SOIL SODICITY AND SALINITY 2 ABSTRACT The objective of this study was to evaluate the effect of continuous use of sewage sludge and treated domestic effluent on the potential risk of soil sodicity and salinity. The experimental design was completely randomized in split plots with ten treatments and five replications. The plots consisted of the use of two types of irrigation water (treated domestic effluent AR and supply water AB) and the subplots by the biosolid doses (0, 50, 100, 150 and 200%) in the years 2012 to 2017. The electrical conductivity (EC), pH, Ca, Mg, Na, RAS and PST of the soil were evaluated. It was concluded that the effect of mineral fertilization (0% - control) with AB was similar to the effluent use in soil EC for the same treatment. Doses from 127.4% and 113.2% of biosolid, respectively, with RA and AB decreased the exchangeable Na content of the soil. Results indicated low risk of sodicity and salinity after five years of use. Keywords: electrical conductivity, sodium, reuse.