Persistence, Distribution, and Emission of Telone C35 Injected into a Florida Sandy Soil as Affected by Moisture, Organic Matter, and Plastic Film Cover

2004 ◽  
Vol 39 (4) ◽  
pp. 505-516 ◽  
Author(s):  
J. E. Thomas ◽  
L.-T. Ou ◽  
L. H. Allen ◽  
L. A. McCormack ◽  
J. C. Vu ◽  
...  
2003 ◽  
Vol 60 (4) ◽  
pp. 390-398 ◽  
Author(s):  
John E Thomas ◽  
L Hartwell Allen ◽  
Leslie A McCormack ◽  
Joseph C Vu ◽  
Donald W Dickson ◽  
...  

2020 ◽  
Vol 23 (3) ◽  
pp. 117-124
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1612 ◽  
Author(s):  
Nikolett Uzinger ◽  
Tünde Takács ◽  
Tibor Szili-Kovács ◽  
László Radimszky ◽  
Anna Füzy ◽  
...  

The short-term effects of processed waste materials: sewage sludge compost (up to 0.5%), biochar made of paper sludge and grain husk (BC) (up to 2%) combined with plant growth-promoting rhizobacterial (PGPR) inoculum, on the fertility of acidic sandy soil at 65% of field capacity were tested in a pot experiment in separate and combined treatments. The soil pH, organic matter content, total and plant-available nutrients, substrate-induced respiration, arbuscular mycorrhizal fungal (AMF) root colonisation parameters and maize (Zea mays L.) biomass were investigated in experiments lasting two months. The positive priming (21% organic matter loss) induced by BC alone was not observed after combined application. The combination of compost and PGPR with 1.5% BC resulted in 35% higher P and K availability due to greater microbial activity compared to BC alone. Only compost applied alone at 0.5% gave a 2.7 times increase in maize biomass. The highest microbial activity and lowest AMF colonisation were found in combined treatments. In the short term the combined application of BC, compost and PGPR did not result in higher fertility on the investigated soil. Further research is needed with a wider range of combined treatments on acidic sandy soil for better understanding of the process.


Geoderma ◽  
2019 ◽  
Vol 342 ◽  
pp. 75-84 ◽  
Author(s):  
Vladimír Šimanský ◽  
Martin Juriga ◽  
Jerzy Jonczak ◽  
Łukasz Uzarowicz ◽  
Wojciech Stępień

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Haiou Zhang ◽  
Jiancang Xie ◽  
Jichang Han ◽  
Haipeng Nan ◽  
Zhen Guo

The degraded aeolian sandy soil in China’s Mu Us Sandy Land requires amendment before it can be suitable for maize or other agricultural production. The addition of material from the local “soft” bedrock can create a new compound soil whose particle composition and structural stability are key issues for sustainable soil development in the region. We used field data from 2010 to 2018 to study the variations in fractal characteristics of compound soil particles at soft rock to sand volume ratios of 1 : 1, 1 : 2, and 1 : 5, along with changes in soil organic matter. Over the study period, all three compound soils showed gradual increases in clay and silt content with corresponding decreasing sand content. The fractal dimension (FD) of particles at ratio 1 : 2 increased by 8.8%, higher than those at 1 : 1 (8.6%) and 1 : 5 (7.7%). The organic matter content (OMC) of particles at ratio 1 : 2 reached a maximum (6.24 ± 0.30 g/kg), an increase of 12 times over the original value. The FD and OMC of particles at ratios 1 : 1 and 1 : 5 were less stable but showed overall increase. The 1 : 2 ratio compound soil was most suitable for maize growth as its clear increase in silt and clay content most improved the texture and OMC of the original sandy soil. Such research has important theoretical and practical significance for understanding the evolutionary mechanism and sustainable use of the compound soil in agriculture within the Mu Us Sandy Land.


Author(s):  
Antonietta Napolitano ◽  
Luigi Santonicola

: This study was conducted to evaluate the behavior of nitrate, moisture and organic matter in a soil with low agronomic input. The test was conducted on silty-sandy soil, a temporal variability of the variables in the different seasons was observed in the three theses. The theses were observed in parallel twice a week. Nitrates showed an increase during the summer-autumn season with higher values ​​in the thesis containing organic matter, “bare soil” followed by the thesis “fallow” and finally by the “cultivated” (see below in experimental set up). The humidity was higher in the “bare soil” thesis followed by “fallow” and “cultivated” one during the summer, in winter the “cultivated” showed the lowest humidity compared to the other two theses. The organic matter does not show great variability in the seasons but is higher in the “fallow” thesis followed by “bare soil” and “cultivated” one. The Montecarlo test informed us that organic matter and humidity were autocorrelated within 5-7.5 m of distance (10-15 lag) while nitrates even if they seemed to be not autocorrelated with each other and have a cyclical pattern.


Soil Research ◽  
1997 ◽  
Vol 35 (1) ◽  
pp. 61 ◽  
Author(s):  
B. P. Degens

An incubation study was conducted to test the effects of decomposing clover tops (added at 0, 6·2 or 12·5 mg organic matter/g soil) and earthworm activity on the contribution of carbohydrate C to the stability of aggregates in a sandy soil. Soils incubated with and without earthworms were separated into surface-casts and bulk soil, and the amounts of water-stable aggregates >1 mm surviving slow and rapid rewetting (when air-dry) in these soil separates were determined. Organic C and acid- and water-extractable carbohydrate C concentrations were determined in the aggregates and bulk soil. The treatments of 6·2 and 12·5 mg organic matter/g soil increased the >1 mm aggregation of the bulk soil by more than 2·2- and 2·8-fold, respectively, compared with the non-amended soils. With the addition of earthworms, there were increases from 1·7- to 1·8-fold only in aggregates surviving slow rewetting. The acid- and water-extractable carbohydrate C contents of aggregates >1 mm in the bulk and surface-cast soils were generally not greater than the carbohydrate C in the bulk soil. Generally, the carbohydrate C fractions were also not increased in the more stable aggregates (rapidly rewet) compared with the weaker aggregates (slowly rewet). Carbohydrate C in bulk soil was generally (P < 0·05) correlated with the amounts of aggregates surviving each rewetting treatment (r > 0·71, P < 0·01). In contrast, greater amounts of carbohydrate in aggregates surviving slow rewetting were not correlated (r < -0·45, P > 0·05), with a greater proportion of these aggregates resisting disruption when the soils were rapidly rewet (except for acid-extractable carbohydrate C; r = -0·84, P < 0·05). These results cast doubt on the usefulness of correlations in assessing the contribution of carbohydrate C to aggregation. The amounts of carbohydrate materials in the soil appeared to have little influence on aggregation, probably because the location of bonding compounds in the soil pore matrix is more critical.


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