Profile Distribution of Carbon Fractions Under Long‐term Rice‐wheat and Maize‐wheat Production in Alfisols and Inceptisols of Northwest India

Abstract

The knowledge of profile distribution of soil organic carbon (SOC) in long-term agricultural systems could help to store atmospheric carbon in the soil. We investigated profile distribution of easily oxidisable Walkley-Black SOC pool (SOC WB ) under long-term ricewheat (R-W) and maize-wheat (M-W) cropping systems under soils of different pedogenesis. The soil samples were collected from the characteristic genetic horizons and analysed for carbon fractions. The SOC WB was the highest in soils under R-W systems in both Alfisols and Inceptisols. The SOC WB stock in the deeper profile horizons under R-W system was significantly (p < 0·05) higher than that under M-W system especially in Typic Hapludalfs. Long-term R-W system could store on average 3·55 Mg ha À1 more SOC WB than M-W system in the Ap horizon. The SOC WB stock in the Ap horizon of all pedons was significantly (p < 0·05) higher in Alfisols than that in Inceptisols. About 60-90% of the total profile SOC WB stock was contributed by B-horizon because of its greater extent. Considering the whole profile, clay was negatively correlated with SOC fractions; however, the SOC fractions were closely related to each other. This study reveals that the distribution of SOC WB is different in long-term R-W and M-W systems not only in surface but also in the deeper horizons and the magnitude of the variation is influenced by the specific pedogenic processes. This indicates the significance of profile SOC WB stock instead of topsoil SOC WB stock in quantifying carbon retention potential of the long-term management practices.

Quantifying the impact of land degradation on crop production: the case of Senegal

“…Therefore, most cultivation techniques aim to optimize the soil organic matter through (zero-)tillage techniques (Costa et al, 2015;Singh et al, 2015), planting of native tree species (Tesfaye et al, 2014), mulching (Mwango et al, 2014), and land use systems (Araya et al, 2010). These activities are not observed in our database but influence the soil organic matter levels at surface and deeper horizons; moreover, the magnitude of variation is also shaped by specific pedogenic processes (Kukal et al, 2014). Hence, with the choice of our approach to test the stability of the relationship between land degradation and crop yield under an increasing level of detail, we hope to have controlled sufficiently for these confounding variables that otherwise might bias the estimation.…”

Environmental Factors Controlling Soil Organic Carbon Stocks in Two Contrasting Mediterranean Climatic Areas of Southern Spain

“…() estimated mean SOC contents of 3·3 kg m −2 in the topsoil (0–20 cm) of cereal crops in Turkey, while Kukal et al . () found mean SOC stocks beneath cereal crops in India of 7·1 kg m −2 in the first 18 cm.…”

“…SOC contents for croplands (5·0 kg m À2 with an average soil depth of 54 cm in SN and 3·0 kg m À2 with an average soil depth of 62 cm in CG) are also lower compared with those found in other regions under similar climatic conditions. For instance, Evrendilek et al (2004) estimated mean SOC contents of 3·3 kg m À2 in the topsoil (0-20 cm) of cereal crops in Turkey, while Kukal et al (2014) found mean SOC stocks beneath cereal crops in India of 7·1 kg m À2 in the first 18 cm.…”

Short‐term Impacts on Soil‐quality Assessment in Alternative Land Uses of Traditional Paddy Fields in Southern Brazil

“…Among the many crops cultivated worldwide according to various agricultural systems, rice is one of the most harmful because of the intense labour that is required and the modifications of the natural cycles that rice production causes (El‐Shahway et al ., ; Tran Ba et al ., ). The alteration and degradation that occur because of rice monocropping are even more important considering the environment in which such cultivation is performed: lowland areas, which play a significant role in regulating C dynamics (Ono et al ., ; Kukal et al ., ).…”