Long‐term manure application for crop yield stability and carbon sequestration in subtropical region

Abstract

Yield stability and carbon sequestration of agricultural systems are impacted by nutrient management strategies. Major objectives of this study were to understand the effects of long-term (43 years) manure application on a) environmental parameters such as soil organic carbon (SOC) sequestration, enzyme activities in surface and subsurface layers, and b) yield, and yield stability under a soybean-wheat cropping system in a Vertisol. For this, 100% recommended dose of nitrogen (N), N and phosphorus (NP), N, P and potassium (NPK), NPK + farmyard manure (NPKM) was compared with an unfertilized control (UC) and a fallow land. After 43 years, NPKM and NPK plots had ∼63 and 30% higher total SOC stock than UC, and 45 and 17% higher total SOC stock than fallow plots, respectively in the 0-30 cm layer. Acid hydrolysable C was ~ 42 and 57% higher for NPKM plots in those layers respectively than fallow land. The proportion of macroaggregates was less than 30% in both soil layers of cultivated plots. NPKM had 44 and 28% greater humic and fulvic acidassociated C than fallow land in top layer. Enzyme activities improved in NPKM by ~ 60 and 61% as compared with fallow land. A steady decline in soybean productivity over the years might be due to residue effect. However, wheat yield increased steadily with manuring. Higher SOC accumulation (p < .001), greater enzyme activities (p < .05), improved structure (p < .05) could enhance wheat yield under NPKM. Thus, manure application could lead to yield stability and enhance SOC sequestration in subtropical region simultaneously.

Long‐term manure application enhances organic carbon and nitrogen stocks in Mollisol subsoil

“…Our findings revealed highly significant positive correlations between SOC stock and TN stock ( R > 0.80), throughout the soil profile (Figure 2b; Table 4), indicating a greater increment in TN stock as a function of increasing SOC stock, respectively, that might depict a close coupling of C and N cycles (Abrar et al, 2021; Falkowski et al, 2000; Soussana & Lemaire, 2014). It is also considered that in the 0–40‐cm layers, the maximum SOC and TN stocks in MNPK compared with CK, M, NPK, and PK were linked with the greater C and N inputs via manure application in MNPK (Gai et al, 2018; Jalali & Ranjbar, 2009; Wankhede et al, 2021), and the higher rhizodeposition (due to greater crop productivity) in the plots treated with MNPK and NPK might be considered the most influencing factors to enhanced soil microbial activity which could increase the mineralization of SOC and TN (Cheng et al, 2016; Malhi & Lemke, 2007). Also, nutrient stoichiometry (C:N ratio) might play a crucial role in nutrient turnover/mineralization (Abrar et al, 2021; Ashraf et al, 2020).…”

Biochemical constituents indicate carbon mineralization under a long‐term integrated nutrient‐supplied Typic Kandiustalf

“…Novara et al (2021) highlighted the significance of cover crops to improve WUE under vineyard and olive plantations in semi‐arid and arid regions under minimum tillage management for sustainable agriculture. Recently, Wankhede et al (2021) observed increased yield with manuring, higher accumulation of SOC (p < 0.001), higher enzyme activity (p < 0.05), and improved soil structure (p < 0.05) under the combined application of NPK with manure in a wheat crop.…”

Silvopasture systems for restoration of degraded lands in a semiarid region of India

“…Yield dent was estimated (Yd; Yd > 0) to assess yield stability. The distance between the bottom 10% (mean of the lowest yielding 4 years of the 40‐year time‐series, Y10) and the time‐series mean (μ) (in kg dry matter ha −1 ) was also computed and referred as yield dent (Yd) (Wankhede et al, 2021). Where : Y10 is the mean yield of lowest yielding 10% years of the time‐series.…”