Return of crop residues to arable land stimulates N2O emission but mitigates NO3− leaching: a meta-analysis

AbstractIncorporation of crop residues into the soil has been widely recommended as an effective method to sustain soil fertility and improve soil carbon sequestration in arable lands. However, it may lead to an increase in the emission of nitrous oxide (N2O) and leaching of nitrate (NO3−) to groundwater due to higher nitrogen (N) availability after crop residue incorporation. Here, we conducted a meta-analysis based on 345 observations from 90 peer-reviewed studies to evaluate the effects of crop residue return on soil N2O emissions and NO3− leaching for different locations, climatic and soil conditions, and agricultural management strategies. On average, crop residue incorporation significantly stimulated N2O emissions by 29.7%, but decreased NO3− leaching by 14.4%. The increase in N2O emissions was negatively and significantly correlated with mean annual temperature and mean annual precipitation, and with the most significant changes occurring in the temperate climate zone. Crop residues stimulated N2O emission mainly in soils with pH ranging between 5.5 and 6.5, or above 7.5 in soils with low clay content. In addition, crop residue application decreased NO3− leaching significantly in soils with sandy loam, silty clay loam, and silt loam textures. Our analysis reveals that an appropriate crop residue management adapted to the site-specific soil and environmental conditions is critical for increasing soil organic carbon stocks and decreasing nitrogen losses. The most important novel finding is that residue return, despite stimulation of N2O emissions, is particularly effective in reducing NO3− leaching in soils with loamy texture, which are generally among the most productive arable soils.

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Crop residue incorporation alters soil nitrous oxide emissions during freeze–thaw cycles

Canadian Journal of Soil Science ◽

10.4141/cjss2012-043 ◽

2013 ◽

Vol 93 (4) ◽

pp. 415-425 ◽

Cited By ~ 23

Author(s):

David E. Pelster ◽

Martin H. Chantigny ◽

Philippe Rochette ◽

Denis A. Angers ◽

Jérôme Laganière ◽

...

Keyword(s):

Nitrous Oxide ◽

Crop Residue ◽

Crop Residues ◽

Sandy Loam ◽

Nitrous Oxide Emissions ◽

Silty Clay ◽

Mineral N ◽

Freeze Thaw ◽

Residue Incorporation ◽

Crop Residue Incorporation

Pelster, D. E., Chantigny, M. H., Rochette, P., Angers, D. A., Laganière, J., Zebarth, B. and Goyer, C. 2013. Crop residue incorporation alters soil nitrous oxide emissions during freeze–thaw cycles. Can. J. Soil Sci. 93: 415–425. Freeze–thaw (FT) cycles stimulate soil nitrogen (N) and carbon (C) mineralization, which may induce nitrous oxide (N2O) emissions. We examined how soybean (Glycine max L.) and corn (Zea mays L.) residue incorporation affect N2O emissions from high C content (35 g kg−1) silty clay and low C content (19 g kg−1) sandy loam soils over eight 10-d FT cycles, as a function of three temperature treatments [constant at +1°C (unfrozen control), +1 to −3°C (moderate FT), or +1 to −7°C (extreme FT)]. In unamended soils, N2O emissions were stimulated by FT, and were the highest with extreme FT. This was attributed to the increased NO3 availability measured under FT. Application of mature crop residues (C:N ratios of 75 for soybean and 130 for corn) caused rapid N immobilization, attenuating FT-induced N2O emissions in the silty clay. In the sandy loam, residue addition also induced immobilization of soil mineral N. However, N2O emissions under moderate FT were higher with than without crop residues, likely because N2O production in this low-C sandy loam was stimulated by C addition in the early phase of incubation. We conclude that FT-induced N2O emissions could be reduced through incorporation of mature crop residues and the subsequent immobilization of mineral N, especially in C-rich soils.

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Qualitative and quantitative response of soil organic carbon to 40 years of crop residue incorporation under contrasting nitrogen fertilisation regimes

Soil Research ◽

10.1071/sr15377 ◽

2017 ◽

Vol 55 (1) ◽

pp. 1 ◽

Cited By ~ 19

Author(s):

Christopher Poeplau ◽

Lisa Reiter ◽

Antonio Berti ◽

Thomas Kätterer

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Crop Residue ◽

Crop Residues ◽

Management Practice ◽

Soil Layer ◽

Clay Fraction ◽

Residue Incorporation ◽

Crop Residue Incorporation ◽

Soc Stocks

Crop residue incorporation (RI) is recommended to increase soil organic carbon (SOC) stocks. However, the positive effect on SOC is often reported to be relatively low and alternative use of crop residues, e.g. as a bioenergy source, may be more climate smart. In this context, it is important to understand: (i) the response of SOC stocks to long-term crop residue incorporation; and (ii) the qualitative SOC change, in order to judge the sustainability of this measure. We investigated the effect of 40 years of RI combined with five different nitrogen (N) fertilisation levels on SOC stocks and five SOC fractions differing in turnover times on a clay loam soil in Padua, Italy. The average increase in SOC stock in the 0–30cm soil layer was 3.1Mgha–1 or 6.8%, with no difference between N fertilisation rates. Retention coefficients of residues did not exceed 4% and decreased significantly with increasing N rate (R2=0.49). The effect of RI was higher after 20 years (4.6Mgha–1) than after 40 years, indicating that a new equilibrium has been reached and no further gains in SOC can be expected. Most (92%) of the total SOC was stored in the silt and clay fraction and 93% of the accumulated carbon was also found in this fraction, showing the importance of fine mineral particles for SOC storage, stabilisation and sequestration in arable soils. No change was detected in more labile fractions, indicating complete turnover of the annual residue-derived C in these fractions under a warm humid climate and in a highly base-saturated soil. The applied fractionation was thus useful to elucidate drivers and mechanisms of SOC formation and stabilisation. We conclude that residue incorporation is not a significant management practice affecting soil C storage in warm temperate climatic regions.

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Comparative effects of crop residue incorporation and inorganic potassium fertilisation on apparent potassium balance and soil potassium pools under a wheat–cotton system

Soil Research ◽

10.1071/sr16200 ◽

2017 ◽

Vol 55 (8) ◽

pp. 723 ◽

Cited By ~ 3

Author(s):

Ning Sui ◽

Chaoran Yu ◽

Guanglei Song ◽

Fan Zhang ◽

Ruixian Liu ◽

...

Keyword(s):

Wheat Straw ◽

Crop Residue ◽

Crop Residues ◽

Water Soluble ◽

K Uptake ◽

Crop Straw ◽

Initial Soil ◽

Residue Incorporation ◽

Crop Residue Incorporation ◽

K Release

The objective of this study was to evaluate the effects of consecutive crop residue incorporation and potassium (K) fertilisation on plant–soil K balance, K forms, K release and K fixation capacity under wheat–cotton rotation at Nanjing and Dafeng in China. Six treatments were evaluated: control (without K input), wheat straw at 0.9tha–1, cotton residue at 0.7tha–1, wheat straw and cotton residue at the aforementioned rates, and 150 and 300kg ha–1 fertiliser K. Treatments in each rotation year had an identical rate of nitrogen and phosphate fertiliser application. The initial soil K content was higher in Dafeng than Nanjing. In the low K content soil of Nanjing, crop K uptake with double crop straw was significantly higher than that under single crop straw return or inorganic fertiliser, and K uptake increased with increasing K inputs. Only double crop straw or 300kg ha–1 fertiliser K treatments reached apparent K balance in Nanjing, but not in Dafeng. The high negative K balance resulted from the elevated K removal by crops in Dafeng. Incorporation of double crop residues favoured accumulation of different forms of K. Application of K fertiliser tended to increase soil water-soluble K, and crop residue incorporation greatly improved non-exchangeable K at a depth of 0–20cm. Similar to K fertiliser, crop residue incorporation significantly increased soil K release and decreased K fixation at both sites. In summary, in a 3-year field experiment, crop residue incorporation and inorganic K fertilisation had similar effects on soil K pools and balance depending on initial soil K level and actual K input.

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Impact of crop residue management on crop production and soil chemistry after seven years of crop rotation in temperate climate, loamy soils

PeerJ ◽

10.7717/peerj.4836 ◽

2018 ◽

Vol 6 ◽

pp. e4836 ◽

Cited By ~ 20

Author(s):

Marie-Pierre Hiel ◽

Sophie Barbieux ◽

Jérôme Pierreux ◽

Claire Olivier ◽

Guillaume Lobet ◽

...

Keyword(s):

Organic Carbon ◽

Crop Production ◽

Crop Residue ◽

Crop Residues ◽

Conventional Tillage ◽

Residue Management ◽

Temperate Climate ◽

Reduced Tillage ◽

Crop Residue Management ◽

The Impact

Society is increasingly demanding a more sustainable management of agro-ecosystems in a context of climate change and an ever growing global population. The fate of crop residues is one of the important management aspects under debate, since it represents an unneglectable quantity of organic matter which can be kept in or removed from the agro-ecosystem. The topic of residue management is not new, but the need for global conclusion on the impact of crop residue management on the agro-ecosystem linked to local pedo-climatic conditions has become apparent with an increasing amount of studies showing a diversity of conclusions. This study specifically focusses on temperate climate and loamy soil using a seven-year data set. Between 2008 and 2016, we compared four contrasting residue management strategies differing in the amount of crop residues returned to the soil (incorporation vs. exportation of residues) and in the type of tillage (reduced tillage (10 cm depth) vs. conventional tillage (ploughing at 25 cm depth)) in a field experiment. We assessed the impact of the crop residue management on crop production (three crops—winter wheat, faba bean and maize—cultivated over six cropping seasons), soil organic carbon content, nitrate (${\mathrm{NO}}_{3}^{-}$), phosphorus (P) and potassium (K) soil content and uptake by the crops. The main differences came primarily from the tillage practice and less from the restitution or removal of residues. All years and crops combined, conventional tillage resulted in a yield advantage of 3.4% as compared to reduced tillage, which can be partly explained by a lower germination rate observed under reduced tillage, especially during drier years. On average, only small differences were observed for total organic carbon (TOC) content of the soil, but reduced tillage resulted in a very clear stratification of TOC and also of P and K content as compared to conventional tillage. We observed no effect of residue management on the ${\mathrm{NO}}_{3}^{-}$ content, since the effect of fertilization dominated the effect of residue management. To confirm the results and enhance early tendencies, we believe that the experiment should be followed up in the future to observe whether more consistent changes in the whole agro-ecosystem functioning are present on the long term when managing residues with contrasted strategies.

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