HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Majumder, B. Articles by Mazumdar, D. PubMed Articles by Majumder, B. Articles by Mazumdar, D. Agricola Articles by Majumder, B. Articles by Mazumdar, D. Related Collections Soil Fertility and Productivity Carbon Sequestration Residue management

SOIL CHEMISTRY

Organic Amendments Influence Soil Organic Carbon Pools and Rice–Wheat Productivity

^a Jadavpur Univ., Kolkata, West Bengal 700 032, India
^b Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal 741 235, India
^c Dep. of Agril. Statistics, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, West Bengal 741 252, India

^* Corresponding author (bidishamajumder{at}yahoo.co.in).

Soil organic C (SOC) pools under long-term management practices provide information on C sequestration pathways, soil quality maintenance, and crop productivity. Farmyard manure (FYM), paddy straw (PS), and green manure (GM) along with inorganic fertilizers were used in a 19-yr-old rice (Oryza sativa L.)–wheat (Triticum aestivum L.) cropping system in subtropical India to evaluate their impact on SOC stock, its different pools—total organic C (C_tot); oxidizable organic C (C_oc) and its four fractions of very labile (C_frac1), labile (C_frac2), less labile (C_frac3), and nonlabile C (C_frac4); microbial biomass C (C_mic); and mineralizable C (C_min). Cropping with only N–P–K fertilization just maintained SOC content, while N–P–K plus organics increased SOC by 24.3% over the control, their relative efficacy being FYM > PS > GM. A minimum of 3.56 Mg C ha^–1 yr^–1 was required to be added as organic amendments to compensate for SOC loss from cropping. The passive (C_frac3 + C_frac4) pool and C_min constituted about 39 and 11.5%, respectively, of C_tot. Organics contributed toward the passive pool in the order FYM > PS > GM. Most of the pools were significantly (P = 0.005) correlated with each other. Yield and sustainable yield index were strongly related with C_frac1, C_oc, C_mic, and C_min. Results suggest C_frac1 as a useful indicator for assessing soil health, and balanced fertilization with FYM as suitable management for sustaining crop productivity of the rice–wheat system.

Abbreviations: BSR, basal soil respiration • C_frac1, very labile carbon • C_frac2, labile carbon • C_frac3, less labile carbon • C_frac4, nonlabile carbon • C_mic, microbial biomass carbon • C_min, mineralizable carbon • C_oc, oxidizable organic carbon • C_tot, total organic carbon • FYM, farmyard manure • GM, green manure • MQ, microbial quotient • PS, paddy straw • qCO₂, respiratory quotient • SOC, soil organic carbon • SYI, sustainable yield index