scholarly journals Dynamics of Microbial Biomass, Nitrogen Mineralization and Crop Uptake in Response to Placement of Maize Residue Returned to Chinese Mollisols over the Maize Growing Season

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1166
Author(s):  
Yan Gao ◽  
Aizhen Liang ◽  
Yan Zhang ◽  
Neil McLaughlin ◽  
Shixiu Zhang ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Nitrogen Mineralization ◽  
Inorganic Nitrogen ◽  
Nitrogen Loss ◽  
N Uptake ◽  
Soil Layer ◽  
Microbial Biomass N ◽  
Growth Stages ◽  
Microbial Biomass Nitrogen ◽  
Maize Growth

Returning residue to soils is not only an effective nutrient management method, but also can reduce the air pollution caused by residue burning, which has become an important factor in global warming. However, it is not clear whether returning residue to the soil can affect the nitrogen mineralization and the nitrogen cycle process, and the environmental impact caused by the nitrogen loss in gaseous forms. Therefore, a pot experiment was conducted to study the effects of residue placement on the nitrogen turnover process, including microbial biomass N (MBN) and C (MBC), inorganic N, crop N uptake, and the contribution of residue-derived N to maize at different maize growth stages. Three treatments were assessed: no residue addition (T0), residue addition to the soil surface (T1), and residue incorporation into the 0–10 cm soil layer (T2). Soil samples were taken at the 0–5 and 5–10 cm layers for all residue treatments. Residue retention (T1 and T2) significantly affected the MBC and MBN contents and decreased MBC/MBN ratio at different maize growth stages. MBC/MBN markedly increased at the R1 stage compared to other growth stages. The differences in total inorganic nitrogen (TIN) were attributed to the balance in net N immobilization and net mineralization in the different maize growth stages. In addition, T2 significantly increased the residue-derived N source for maize by 11.3% compared to T0 in the R3 growth stage. Overall, relative to T1, T2 is a better agriculture management measure to promote N transformation and supply, and enhance residue-derived N release and uptake in maize.

scholarly journals Comparison of inorganic nitrogen uptake dynamics following snowmelt and at peak biomass in subalpine grasslands

2013 ◽  
Vol 10 (11) ◽  
pp. 7631-7645 ◽  
Author(s):  
N. Legay ◽  
F. Grassein ◽  
T. M. Robson ◽  
E. Personeni ◽  
M.-P. Bataillé ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Plant Communities ◽  
Inorganic Nitrogen ◽  
N Uptake ◽  
Microbial Biomass N ◽  
Inorganic N ◽  
Peak Biomass ◽  
Biomass N ◽  
Subalpine Grasslands

Abstract. Subalpine grasslands are highly seasonal environments and likely subject to strong variability in nitrogen (N) dynamics. Plants and microbes typically compete for N acquisition during the growing season and particularly at plant peak biomass. During snowmelt, plants could potentially benefit from a decrease in competition by microbes, leading to greater plant N uptake associated with active growth and freeze-thaw cycles restricting microbial growth. In managed subalpine grasslands, we expect these interactions to be influenced by recent changes in agricultural land use, and associated modifications in plant and microbial communities. At several subalpine grasslands in the French Alps, we added pulses of 15N to the soil at the end of snowmelt, allowing us to compare the dynamics of inorganic N uptake in plants and microbes during this period with that previously reported at the peak biomass in July. In all grasslands, while specific shoot N translocation (per g of biomass) of dissolved inorganic nitrogen (DIN) was two to five times greater at snowmelt than at peak biomass, specific microbial DIN uptakes were similar between the two sampling dates. On an area basis, plant communities took more DIN than microbial communities at the end of snowmelt when aboveground plant biomasses were at least two times lower than at peak biomass. Consequently, inorganic N partitioning after snowmelt switches in favor of plant communities, allowing them to support their growing capacities at this period of the year. Seasonal differences in microbial and plant inorganic N-related dynamics were also affected by past (terraced vs. unterraced) rather than current (mown vs. unmown) land use. In terraced grasslands, microbial biomass N remained similar across seasons, whereas in unterraced grasslands, microbial biomass N was higher and microbial C : N lower at the end of snowmelt as compared to peak biomass. Further investigations on microbial community composition and their organic N uptake dynamics are required to better understand the decrease in microbial DIN uptake.

scholarly journals Seed Meals from Brassicaceae Oilseed Crops as Soil Amendments: Influence on Carrot Growth, Microbial Biomass Nitrogen, and Nitrogen Mineralization

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 354-361 ◽  
Author(s):  
André Snyder ◽  
Matthew J. Morra ◽  
Jodi Johnson-Maynard ◽  
Donald C. Thill
Keyword(s):  
Microbial Biomass ◽  
Degradation Products ◽  
N Uptake ◽  
Biologically Active ◽  
Microbial Biomass N ◽  
Glucosinolate Content ◽  
N Availability ◽  
Fresh Market ◽  
Microbial Biomass Nitrogen ◽  
Total N

Brassicaceae seed meals (BSMs) average 6% nitrogen (N) by weight and contain glucosinolates (GLSs) that produce biologically active compounds. A two-season field study was initiated to determine how Brassica juncea L., Brassica napus L., and Sinapis alba L. seed meals, each with different glucosinolate profiles, alter carrot (Daucus carota L. subsp. sativus) growth, microbial biomass N (MBN), and soil N mineralization. BSM applications of 1 and 2 t·ha−1 36 days before planting did not influence carrot emergence, whereas carrot emergence decreased up to 40% in S. alba treatments seeded 15 days after BSM application. Crop quality was unaffected by BSM treatments and total fresh market yields were equal to or higher than the unamended controls in both years. At 4 and 8 days after seed meal application, MBN in the high-GLS B. juncea and S. alba treatments was 48% to 67% lower than in the low-GLS B. napus treatment. Seasonal apparent net N mineralized expressed as a percentage of the total N applied in the seed meals was unaffected by glucosinolate concentration and ranged from 30% to 81% across both years. BSMs can be used to increase soil inorganic N and carrot yields, but crop phytotoxicity is possible depending on the meal and its respective glucosinolate content. GLS degradation products inhibit microbial N uptake in the short term, but longer-term N availability is not compromised.

Changes in soil carbon and nitrogen under long-term cotton plantations in China

2011 ◽  
Vol 149 (4) ◽  
pp. 497-505 ◽  
Author(s):  
W. KAIYONG ◽  
F. HUA ◽  
T. RANAB ◽  
M. A. HANJRAC ◽  
D. BO ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Soil Layer ◽  
Control Site ◽  
Available Nitrogen ◽  
Microbial Biomass Nitrogen ◽  
Effective Measure ◽  
Soil Microbial ◽  
Time Substitution

SUMMARYCotton is the dominant crop in the northern Xinjiang oasis of China; it accounts for 0·78 of the total planting area and represents a major contribution to economic development. The objective of the present study is to determine how cotton plantation age affected chemical and microbiological properties of the soil. The time substitution method was used on plantation farmlands, reclaimed from uncultivated land 0, 5, 10, 15 and 20 years ago. A total of 250 soil samples, at depths of 0–200, 200–400, 400–600, 600–800 and 800–1000 mm, were collected from cotton fields in 10 farms of each age category. There were significant differences in soil organic carbon (SOC), total soil nitrogen (TSN), soil available nitrogen (SAN), soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN). There were also differences in the activities of cellulase, invertase and urease between soil layers and plantation ages, and these were most evident in the 200–400 mm layer. The cumulative rates of SOC and SMBC in the 0–1000 mm soil layer at the 5-, 10-, 15- and 20-year sites were 0·89, 0·99, 1·01 and 0·92 mg/kg/yr and 16, 16, 16 and 15 mg/kg/yr, respectively, compared to that at the control site (0 year). The cumulative amounts of SOC and SMBC increased gradually and then decreased, reaching a maximum at plantation ages of 13·1 years and 11·1 years, respectively. This suggests that incorporation of post-harvest cotton residues could be used as an effective measure to improve SOC in farmland of Xinjiang Oasis, and may be recommended for adoption in cotton growing in semi-arid oasis agriculture.

scholarly journals Biochar Promotes Nitrogen Transformation and Tomato Yield by Regulating Nitrogen-Related Microorganisms in Tomato Cultivation Soil

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 381
Author(s):  
Lili Guo ◽  
Huiwen Yu ◽  
Wenquan Niu ◽  
Mourad Kharbach
Keyword(s):  
Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
N Uptake ◽  
Management Strategies ◽  
Application Rate ◽  
Significant Loss ◽  
Inorganic N ◽  
Microbial Biomass Nitrogen ◽  
N Transformation ◽  
Tomato Yield

Nitrogen (N) transformation in soil directly determines the effectiveness of N for plant growth. Biochar has received evermore attention because of its significant ability to improve soil. However, the effects of biochar on N-related microorganisms (Lycopersicon esculentum Mill.) in tomato cultivation soil, N transformation, utilisation of water and N fertiliser, and tomato yield remain unclear. The objective of this study was to investigate the responses of N-related microorganisms to biochar and N fertilisation in soil, along with the implications of biochar for altering N transformation, N uptake by tomatoes, and utilisation of water and N fertiliser. A two-year greenhouse experiment containing six biochar levels under drip irrigation (0, 10, 30, 50, 70, and 90 t ha−1) and two N fertiliser application rates (190 and 250 kg ha−1) was conducted in the northwest of China. The results showed that adding biochar significantly promoted urease activity, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and the number of amoA-type nitrifiers in the soil. The MBC:N ratio and the number of nirS-type denitrifiers were significantly inhibited when the added amount of biochar was greater than or equal to 30 t ha−1. Moreover, biochar can increase the water content in the soil and can reduce the N lost to leaching. The inorganic N (NO3− and NH4+) in the soil could be better maintained in the rootzone and better absorbed by tomato plants when adding 30, 50, and 70 t ha−1 of biochar. The amount of N fertiliser could be reduced by 24% without a significant loss of tomato yield when the amount of biochar added was over 30 t ha−1. It was indicated that the yield of tomatoes and the net profits were quadratically related to the application rate of biochar. In the test area, 53 t ha−1 of biochar with 190 kg ha−1 of N and 44.6 t ha−1 of biochar with 190 kg ha−1 of N were calculated to be the best amounts from the perspectives of tomato yield and net profit, respectively. Thus, biochar promotes N transformation by regulating N-related microorganisms; hence, it increases the inorganic N in the roots of the plants, reduces N lost to leaching, and significantly promotes the N absorption of tomatoes. The results in this research are of great significance for the development of management strategies for tomato maintenance, environmental protection, and resource conservation.

scholarly journals Changes in Nitrogen Pools in the Maize—Soil System after Urea or Straw Application to a Typical Intensive Agricultural Soil: A 15N Tracer Study

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1134
Author(s):  
Jie Zhang ◽  
Ping He ◽  
Dan Wei ◽  
Liang Jin ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Chemical Fertilizer ◽  
Bulk Soil ◽  
15N Tracer ◽  
Organic N ◽  
Microbial Biomass N ◽  
Rhizospheric Soil ◽  
Soil System ◽  
Maize Growth ◽  
Biomass N

A maize pot experiment was conducted to compare the difference of N distribution between bulk and rhizospheric soil after chemical fertilizer with or without soil straw amendment at an equivalent N rate using a 15N cross-labeling technique. Soil N pools, maize N and their 15N abundances were determined during maize growth. The urea plus straw treatment significantly (p < 0.05) increased the recovery of urea N in soil and 26.0% of straw N was assimilated by maize. Compared with urea treatment in bulk soil, urea plus straw treatment significantly (p < 0.05) increased the concentration and percentage of applied N as dissolved organic N (DON) and microbial biomass N (MBN) from milk stage to maturity, increased those as particulate organic N (PON) and mineral associated total N (MTN) throughout maize growth and decreased those as inorganic N (Inorg-N) from the eighth leaf to the silking stage. Compared with bulk soil, rhizospheric soil significantly (p < 0.05) decreased the concentration and percentage of applied N as PON and increased those as Inorg-N and MTN in both applied N treatments from the silking stage, and significantly (p < 0.05) decreased the concentration and percentage of applied N as microbial biomass N (MBN) in the urea plus straw treatment. Overall, straw N was an important N source and combined application of chemical fertilizer with straw increased soil fertility, with the rhizosphere regulating the transformation and supply of different N sources in the soil–crop system.

scholarly journals Comparison of inorganic nitrogen uptake dynamics following snowmelt and at peak biomass in subalpine grasslands

2013 ◽  
Vol 10 (5) ◽  
pp. 8887-8917 ◽  
Author(s):  
N. Legay ◽  
F. Grassein ◽  
T. M. Robson ◽  
E. Personeni ◽  
M.-P. Bataillé ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Microbial Communities ◽  
Plant Communities ◽  
N Uptake ◽  
Microbial Biomass N ◽  
Inorganic N ◽  
Peak Biomass ◽  
Biomass N ◽  
Subalpine Grasslands

Abstract. Subalpine grasslands are highly seasonal environments and likely subject to strong variability in nitrogen (N) dynamics. Plants and microbes typically compete for N acquisition during the growing season and particularly at plant peak biomass. During snowmelt, plants could potentially benefit from a decrease in competition by microbes because of greater plant N uptake associated with active growth and freeze-thaw cycles restricting microbial growth. In managed subalpine grasslands, we expect these interactions to be influenced by recent changes in agricultural land-use, and associated modifications in plant and microbial communities. At a subalpine grassland site in the Central French Alps, a pulse of 15N was added to the soil at the end of snowmelt, allowing us to compare the dynamics of inorganic N uptake in plants and microbes during this period with that previously reported at the peak biomass in July. In all grasslands, specific plant (per g of biomass) dissolved inorganic N (DIN) uptake was two to five times greater at snow-melt than at peak biomass, whereas the specific microbial DIN uptakes were similar between the two sampling dates. On an area basis, plant communities took more DIN than microbial communities at the end of snowmelt, and the intensity of this DIN uptake by plants differed across land use types. Consequently, N partitioning after snowmelt switches in favor of plant communities allowing them to support their growing capacities at this period of the year. Seasonal differences in microbial and plant N-related dynamics were also affected by past (terraced vs. unterraced) rather than current (mown vs. unmown) land use. In terraced grasslands, microbial biomass N remained similar across seasons, whereas in unterraced grasslands, microbial biomass N was higher and microbial C : N lower at the end of snowmelt as compared to peak biomass. Further investigations on microbial community composition and their organic N uptake dynamics are required to better understand the decrease in microbial DIN uptake.

Effects of warming and oxalic acid addition on plant–microbial competition in Picea brachytyla

2021 ◽  
pp. 1-8
Author(s):  
Weilong Liu ◽  
Gang Xu ◽  
Jingwei Bai ◽  
Baoli Duan
Keyword(s):  
Microbial Biomass ◽  
Oxalic Acid ◽  
Soil Microorganisms ◽  
Fine Root ◽  
Inorganic Nitrogen ◽  
N Recovery ◽  
Microbial Biomass Nitrogen ◽  
Acid Addition ◽  
Tracer Techniques ◽  
Fine Root Length

The importance of oxalic acid for tree seedling growth and the competition for inorganic nitrogen (N) by plants and soil microorganisms under warming was investigated using 15N tracer techniques in Picea brachytyla (Franch.) E. Pritz. Results showed that warming combined with oxalic acid application induced growth enhancements in seedlings primarily through increases in fine root length and fine root surface area. Moreover, soil NH4 +, NO3 –, PO4 3–, N mineralization, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) were significantly higher or tended to be higher with oxalic acid application. However, warming with oxalic acid application altered the partitioning of N between plants and soil microorganisms by increasing microbial 15N recovery to a lesser extent than it increased plant 15N recovery. While plants showed no specific preferences between N forms under normal conditions or warming alone, under warming and oxalic acid, plants showed a preference for 15NO3. Microorganisms showed a stronger preference for 15NH4 especially under warming and oxalic acid treatments. These findings suggest that plasticity in resource use could be an important mechanism in alleviating competition for soil N between plants and microbes under warming and oxalic acid addition.

Corrigendum to: Early growing season immobilisation affects post-tillering wheat nitrogen uptake from crop stubble and 15N fertiliser in a sandy soil

Soil Research ◽  
2021 ◽  
Vol 59 (3) ◽  
pp. 318
Author(s):  
Pilar Muschietti Piana ◽  
Therese Marie McBeath ◽  
Ann Marie McNeill ◽  
Pablo Ariel Cipriotti ◽  
Vadakattu Gupta
Keyword(s):  
Microbial Biomass ◽  
Sandy Soil ◽  
N Uptake ◽  
Early Growth ◽  
Wheat Crop ◽  
Growth Stages ◽  
N Availability ◽  
Soil System ◽  
N Supply ◽  
Energy Limitation

In semiarid sandy soil environments there is a dual challenge of carbon and nitrogen (N) limitation that needs to be managed to ensure timely supply of N to crops. Management of N inputs to soil using combinations of legume stubble addition and fertiliser N in cereal systems is essential to meet crop demand and maintain N in soil organic matter. The aim of this study was to assess soil mineral and biological N pools that influence N supply and N uptake of wheat at early growth stages. The recovery of 15N-labelled fertiliser by wheat was evaluated using a factorial combination of either wheat, lupin or no stubble incorporated with or without 15N fertiliser in a sandy soil system. Soil and plant samples were collected at sowing, tillering, first node and booting to monitor changes in N pools and 15N uptake by the wheat. Crop stubble incorporation one week before sowing increased biological N pools in the surface soil (0–10 cm). Early N immobilisation (sowing–tillering) in all the treatments without 15N fertiliser may have limited N availability for wheat uptake in the subsequent period (tillering–first node), when fertiliser N appeared critical to maximise N supply for plant requirements. Up to 38% of the 15N fertiliser applied at sowing was incorporated into the soil microbial biomass pool, so that fertiliser N was critical to relieve short-term inherent N limitations for both plant and microbial growth, and to supply the longer-term biological pools (microbial biomass) to support subsequent mineralisation potential. Reducing the energy limitation to the microbial pool through inputs of carbon from stubble was also critical to ensure fertiliser N supplied sufficient N to satisfy plant demand later in the growing period. These results have implications for management decisions on semiarid sandy soil systems that aim to synchronise N from inputs of legume stubbles and fertiliser with crop N demand during early growth stages of wheat.

Nitrogen uptake efficiency of maize in monoculture and intercropped with Brachiaria humidicola and Panicum maximum in a dystrophic Red-Yellow Latosol of the Brazilian Cerrado

2016 ◽  
Vol 67 (1) ◽  
pp. 47 ◽  
Author(s):  
Thais Rodrigues Coser ◽  
Maria Lucrécia Gerosa Ramos ◽  
Cícero Célio de Figueiredo ◽  
Segundo Urquiaga ◽  
Arminda Moreira de Carvalho ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Cover Crops ◽  
N Uptake ◽  
Microbial Biomass N ◽  
Panicum Maximum ◽  
No Tillage ◽  
Available N ◽  
Brachiaria Humidicola ◽  
Uptake Efficiency ◽  
Biomass N

No-tillage systems associated with intercropping practices of grains and forages as cover crops are increasing in the Cerrado agricultural areas. The aim of this study was to quantify the nitrogen (N) uptake efficiency of maize (Zea mays L.) grown as monoculture and intercropped with tropical forages under a no-tillage system by using the 15N isotope tracer in conjunction with measurements of soil microbial biomass N and available soil N. The experiment was conducted in the 2010–11 growing season, in a Dystrophic Red-Yellow Latosol (Typic Haplustox) in the Cerrado. The experiment was established in a complete randomised block design with three replicates with the following treatments: maize monoculture; maize intercropped with Panicum maximum Jacq. cv. Aruana; and maize intercropped with Brachiaria humidicola (Rendle) Schweick. Nitrogen was applied as ammonium sulfate at a rate of 100 kg ha–1 (30 kg N ha–1 was applied at planting and 70 kg N ha–1 as a side-dressing). The N-fertiliser uptake efficiency in maize and grain yield was not affected by the presence of the intercropped forages. The intercropped B. humidicola and P. maximum recovered 2.08% and 3.71% of the N fertiliser applied, respectively. The soil was the main N source for maize. Maize intercropped with P. maximum showed higher values of microbial biomass N and available N in the soil.

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