Quantifying the effect of soil organic matter on indigenous soil N supply and wheat productivity in semiarid sub-tropical India |
| |
Authors: | D K Benbi Milap Chand |
| |
Affiliation: | (1) Department of Soils, Punjab Agricultural University, Ludhiana, 141004, India |
| |
Abstract: | A field experiment was conducted on a loamy sand soil for six years to quantify the effect of soil organic matter on indigenous
soil N supply and productivity of irrigated wheat in semiarid sub-tropical India. The experiment was conducted by applying
different combinations of fertilizer N (0–180 kg N ha−1), P (0–39 kg P ha−1) and K (0–60 kg K ha−1) to wheat each year. For the data pooled over years, fertilizer N together with soil organic carbon (SOC) and their interaction
accounted for 75% variation in wheat yield. The amount of fertilizer N required to attain a yield goal decreased as the SOC
concentration increased indicating enhanced indigenous soil N supply with an increase in SOC concentration. Besides SOC concentration,
the soil N supply also depended on yield goal. For a yield goal of 4 tons ha−1, each ton of SOC in the 15 cm plough layer contributed 4.75 kg N ha−1 towards indigenous soil N supply. An increase in the soil N supply with increase in SOC resulted in enhanced wheat productivity.
The contribution of 1 ton SOC ha−1 to wheat productivity ranged from 15 to 33 kg ha−1 across SOC concentration ranging from 3 to 9 g kg-1 soil. The wheat productivity per ton of organic carbon declined curvilinearly as the native SOC concentration increased.
The change in wheat productivity with SOC concentration shows that the effect of additional C sequestration on wheat productivity
will depend on the existing SOC concentration, being higher in low SOC soils. Therefore, it will be more beneficial to sequester
C in soils with low SOC than with relatively greater SOC concentration. In situations where the availability of organic resources
for recycling is limited, their application may be preferred in soils with low SOC concentration. The results show that an
increase in C sequestration will result in enhanced wheat productivity but the increase will depend on the amount of fertilizer
applied and the existing fertility level of the soil. |
| |
Keywords: | Carbon sequestration N use efficiency Nitrogen availability Soil N supply Wheat productivity |
本文献已被 SpringerLink 等数据库收录! |
|