Zone Tillage Research Articles

Pharmacoinvasive Therapy in Treating Acute STEMI Patients in Covid-19 Era

Background: Treating acute ST segment elevated myocardial infarction (STEMI) patients by primary PCI (pPCI) has dramatically fallen globally in covid era as there is chances of potential threat of spreading COVID among the non-COVID patients. Thereby, thrombolysis of acute STEMI patient in grey zone till COVID RT PCR report to come, was the mode of treatment of acute myocardial infarction patient in our hospital. We have carried out this prospective observational study to see the outcomes of thrombolysis and subsequent intervention. Methods: STEMI patient who presented to our emergency department with chest pain and ECG and hs-Troponin-I evidenced acute STEMI, were enrolled in the study. Total 139 patients enrolled (Male:120, Female :54); average age for Male: 54 yrs., female was: 56yrs. All patients were admitted in the grey zone of CCU where thrombolysis was done. COVID-19 patients were excluded from intervention and managed conservatively. Covid Negative patients were kept transferred to CCU green zone. On average 2.1 days after Fibrinolysis, elective PCI carried out. Data analysis from 48 patients who underwent pharmacoinvasive therapy was done. Results: Among the study population, Covid-19 positive was in 11 (7.9%) patients and Covid-19 was negative in 128 (92.1%) patients. Primary PCI was performed in 7 (5.03%) patients. Rest of the patients were managed by Pharmacoinvasive therapy. Thrombolysis by Tenecteplase (TNK) was done in 89 (64%) patients, and by Streptokinase in 25 (17.9%) patients, 18 (12.9%) patients did not receive any thrombolysis due to late presentation. Chest pain to needle time was 7.2 ±12.7hrs., thrombolysis to balloon time was 117.5 ±314.8hrs. More than 50% stenosis resolution observed in 20 (41.6%) patients, chest pain resolution within one hour of thrombolysis observed in 21 (43.8%) patients. Ten (20.8%) patients developed. Door to needle time was 30 mins. Total, 88 stents were deployed in 83 territories. CABG was recommended for 7 (5.03%) patients. Stented territory was LAD 37 (45.7%) and RCA 32 (39.5%) and LCX 12 (14.8%). Conclusion: In the era of COVID-19, in this prospective cohort study, on acute STEMI patient management, we found that Pharmacoinvasive therapy, reduced patients’ symptoms and ST resolution occurred partially. Cardiovasc j 2023; 15(2): 136-143

Maize performance in a kura clover living mulch under drought conditions

AbstractRow establishment is important to mitigate competition with maize (Zea mays L.) seedlings in a kura clover (Trifolium ambiguum Bieb.) living mulch (KCLM). This study investigated the effect of row‐establishment and fertilizer nitrogen (N) rate on maize yield and N uptake in a KCLM system in Arlington, WI, and Rosemount, MN, during the 2021 growing season. Row establishment treatments included rotary zone tillage (RZT), shank strip‐tillage (ST), and banded herbicides (BH), each evaluated at six N rates from 0 to 225 kg N ha−1. Extended periods of moderate and severe drought were experienced during the study period. The Arlington and Rosemount sites received 64 and 63% of the normal precipitation between 20 Apr. and 31 Oct. 2021, but poor distribution and higher temperatures at Rosemount elevated drought severity indices at that site. Grain yields at Rosemount were 3.6 Mg ha−1, whereas Arlington produced yields that matched expectations for the area (10 Mg ha−1). Row establishment affected maize grain yield differentially at each site, where, under severe drought conditions, BH maximized maize yield, whereas under moderate drought conditions, the higher level of tillage (RZT) maximized maize yield. These responses are most likely attributed to reduced moisture loss in the row‐zone of the BH treatment and the greater level of clover suppression in the RZT treatment and their interactions with specific weather conditions at the research sites. Results from this study indicate that row establishment methods in a KCLM cropping system should be considered with spring environmental conditions and the expected weather outlook.

Spatiotemporal distribution of roots in a Maize-Kura clover living mulch system: Impact of tillage and fertilizer N source

Kura clover living mulch (KCLM) can be integrated into Midwestern row-crop production systems as a soil and water conservation tool. Rotary zone tillage is currently recommended to establish a clover-free zone for maize seeding in the living mulch, however, this practice is costly and presents a major barrier to producers. Banding anhydrous NH3 in a KCLM, due to its transient caustic impact, may damage clover roots and provide supplemental clover suppression. This experiment aimed to determine the effects of tillage intensity and fertilizer source on maize yield and clover root biomass. Maize was seeded into a KCLM prepared with rotary zone tillage (RZT) or shank strip tillage (ST) and fertilized with ammonium nitrate (NH4NO3) or NH3 banded under the tilled zone. Aboveground clover biomass, total root biomass, and soil N were sampled at eight times between tillage and the R4 maize physiological growth stage, and maize and clover roots were differentiated using their 13C isotope signatures. Results indicated that ST achieved adequate clover suppression and grain yields were not affected by tillage or fertilizer treatments. The RZT treatment reduced clover root biomass relative to ST, but fertilizer N source did not affect above or belowground clover biomass pools. Based on the results of this study, we conclude that ST can be used with any form of banded N fertilizer to successfully manage maize in KCLM while maintaining a greater level of clover root biomass than RZT.

Extending Cover Crop Benefits with Zone Till Management in Northern Organic Summer Squash Production

Winter annual legume cover crops often fail to reach full maturity by spring vegetable planting dates in northern climates, which prevents maximum nitrogen (N) contributions. To determine if delayed termination improved cover crop biomass and N content, we evaluated winter rye + hairy vetch (Secale cereale L. + Vicia villosa Roth) and oat + field pea (Avena sativa L. + Pisum sativum L.) cover crop mixtures in 2015 and 2016, and medium red clover (Trifolium pratense L.) in 2016, in zone-tilled organic yellow crookneck squash (Cucurbita pepo var. torticollis Harz). In-row regions where cover crops were terminated in early spring during crop row preparation were compared to between-row regions where termination was delayed until legume maturation in late spring. Soil quality (soil inorganic N, permanganate oxidizable C (POXC), and potentially mineralizable N (PMN)) was also determined for in-row and between-row regions at four time points throughout the growing season. In 2015, winter rye + hairy vetch biomass N more than doubled between early and late termination times, with 120 and 258 kg N ha−1, respectively. Permanganate oxidizable C was not responsive to cover crop systems or tillage, and only slightly decreased over time in 2016. Soil inorganic N and PMN after cover crop termination in 2016 provided evidence of localized soil N cycling responses to cover crop termination in in-row and between-row regions. The extended growing period for cover crops between crop rows in the first several weeks of crop growth had no negative effect on crop yield, and appeared to enhance soil fertility.

Cover Image, Volume 113, Issue 3

On the cover: Manure injector with chisel and sweep tools utilized in zone tillage depth and tillage intensities studies conducted in western New York between 2012 and 2016. See the article, “Conservation tillage is compatible with manure injection in corn silage systems”, by Ketterings et al. in this issue of Agronomy Journal. Photo Credit: Quirine M. Ketterings. image

Conservation tillage is compatible with manure injection in corn silage systems

AbstractAdoption of conservation tillage practices has increased over the past 30 yr in the United States. Research is needed to evaluate if reduced tillage practices are compatible with manure injection on dairy farms. Two corn (Zea mays L.) silage studies were conducted in New York to evaluate the impact of zone tillage depth and tillage intensity on early plant growth and soil nitrate‐N, corn silage productivity and quality, and nutrient uptake at harvest. Treatments included three zone tillage depths (0, 18, and 36 cm; with aerator seedbed preparation) for Study 1 (2012–2013) and three tillage intensities (no tillage, reduced tillage [aerator seedbed preparation without zone tillage], and intensified reduced tillage [aerator seedbed preparation plus zone tillage at 18‐cm depth]) for Study 2 (2014–2016). Manure was injected in the spring, and all fields had a manure and zone tillage history. Zone tillage depth did not affect early plant growth, soil nitrate‐N content at V5‐V6, corn silage yield, quality, corn stalk nitrate test (CSNT)‐N, or nutrient removal with harvest. The CSNT‐N levels exceeded 2,000 mg NO3–N kg–1, confirming sufficient N for each treatment. Study 2 showed no impact of tillage intensity on corn growth, yield, or nutritive value, and CSNT‐N levels always exceeded 2,000 mg NO3–N kg–1. These findings show that, on fields with a history of manure addition and reduced tillage, manure injection followed by planting without further seedbed preparation or zone tillage can maintain yields and quality and can conserve N while reducing soil disturbance and tillage‐associated fuel, equipment, and labor costs.

Influence of reef flat submergence on infra-gravity wave energy and resonance over the fringing reef

Fringing reefs which are common nearshore islands with coral reef growth have special topography of very steep slope on the fore-reef and mild slope on the wide flat. When incident waves propagate from a very deep water region (from hundreds of meters to thousands of meters of depth) to approaching the reef they abruptly commence a very shallow water (only few centimeters to several meters of depth) and create strong hydrodynamic processes on the reef flat. Due to shallow depth, waves feel the bottom and break in the area of fore-reef slope and reef crest and partial reef flat. Infra-gravity waves (IG), other name as bound long waves or surf beat, which belong to low-frequency wave type (0.002Hz ¸ 0.04Hz) are generated by the varying-breaking point mechanism on the shallow reef flat. On the flat, short wave energy is almost dissipated; low-frequency waves are strongly dominated over the surf zone till swash zone. Wave set-up causing an increase of water level on the flat combines with the run-up at the shoreline which can lead to coastal flooding. Besides, if the reef flat length is in the order of one fourth of wavelength the first oscillation resonant mode with standing wave occurs. This component is resonantly amplified at the shoreline relative to the incident infra-gravity wave energy at the reef crest.

Investigation of the filament spatial structure by aberration focusing in air of a femtosecond radiation pulse

The appearance conditions of two filaments propagating at an angle to each other by aberration focusing in air of femtosecond radiation pulse with a 940 nm wavelength are studied. Interest to these beams is due to the formation of highly directed radiation of the white supercontinuum in them with diffraction divergence. It is shown that the pump beam diffraction on plasma and Kerr nonlinearity in filamentation area are responsible for the formation of two additional filaments. The diffraction maxima are beginnings of high-intensity pump beams due to Kerr self-focusing of surrounding energy reservoir of pump radiation. The dynamics of these beams from foci zone till far zone is demonstrated.

Living Mulch Management Spatially Localizes Nutrient Cycling in Organic Corn Production

Kura clover (Trifolium ambiguum) is a perennial living mulch species that can be used in conjunction with zone tillage to reduce nitrogen pollution, maintain ground cover, and provide nitrogen to crops. In such systems, kura clover is maintained between crop rows by limiting tillage only to within-row areas. However, the effect of zone-tilled living mulches on soil quality and nutrient cycling in these distinct regions is relatively unexplored. We examined three pools of labile soil organic matter (SOM): microbial biomass, particulate organic matter (POM), and permanganate oxidizable carbon (POXC). Soil samples were collected from both within-row and between-row locations of a zone-tilled kura clover living mulch at three time points per year: before spring zone tillage, approximately ten days after spring zone tillage and corn (Zea mays) planting, and at corn harvest in 2015 and 2016. In 2016, POM and POXC decreased within rows relative to between-row regions after tillage, suggesting that zone till management stimulated decomposition of readily available SOM to effectively localize nutrient cycling in this region and slow mineralization between rows where living kura clover remained. This work shows that zone-tilled living mulches may be a promising avenue for enhancing the synchrony of nutrient mineralization specifically within crop rows, while maintaining year-round ground cover between rows.

Assessment of Groundwater Contamination by Terbuthylazine Using Vadose Zone Numerical Models. Case Study of Valencia Province (Spain).

Terbuthylazine is commonly used as an herbicide to control weeds and prevent non-desirable grow of algae, fungi and bacteria in many agricultural applications. Despite its highly negative effects on human health, environmental modeling of this kind of pesticide in the vadose zone till reaching groundwater is still not being done on a regular basis. This work shows results obtained by two mathematical models (PESTAN and PRZM-GW) to explain terbuthylazine behavior in the non-saturated zone of a vertical soil column. One of the models use a one-dimensional analytical formulation to simulate the movement of terbuthylazine through the non-saturated soil to the phreatic surface. The second and more complex model uses a whole set of parameters to solve a modified version of the mass transport equation considering the combined effect of advection, dispersion and reactive transport processes. Both models have been applied as a case-study on a particular location in South Valencia Aquifer (Spain). A whole set of simulation scenarios have been designed to perform a parameter sensitivity analysis. Despite both models leading to terbuthylazine’s concentration values, numerical simulations show that PRZM-GW is able to reproduce concentration observations leading to much more accurately results than those obtained using PESTAN.

Conservation production systems in the mid‐southern USA: III. Zone tillage for furrow‐irrigated soybean

AbstractMid‐southern U.S. soybean [Glycine max (L.) Merr.] producers are frequently encouraged to adopt no‐tillage systems to capture the associated environmental benefits; however, adoption is minimal due to the need for raised seedbeds for irrigation and drainage purposes. This research was conducted to determine if zone tillage systems, with and without a tillage radish (Raphanus sativus L. var. longipinnatus) cover crop, can maintain yield, profitability, and water use efficiency relative to that of a conservation tillage system with subsoiling. The effects of conservation systems on soybean grain yield, net returns above specified costs, and water use efficiency were investigated near Stoneville, MS on a Dubbs silt loam (Fine‐silty, mixed, active, thermic Typic Hapludalfs). Relative to a conservation tillage system with subsoiling, switching to a zone tillage system with or without a cover crop had no effect on soybean grain yield (P = .4986), net returns above specified costs (P = .3724), or water use efficiency (P = .5652). Our data indicate that mid‐southern U.S. soybean productivity and profitability are maintained in zone‐tillage systems.

Tillage system influences hydrophobicity but not water repellency of a clay loam soil in southwestern Ontario

A 21 yr field study comparing zone tillage (ZT), no-tillage (NT), and moldboard plow tillage (MP) was used to elucidate tillage effects on soil hydrophobicity (SH) and soil water repellency index (RI) in a cool, humid clay loam soil in southwestern Ontario. The SH was 38% (P ≤ 0.05) greater for ZT and NT than MP, and it was similar between crop row (0.34) and crop inter-row (0.37) for ZT. The RI values were not different among tillage systems, or between the crop row versus crop inter-row positions under the three tillage systems.

Tillage intensity influences nitrogen cycling in organic kura clover living mulch

Perennial cover crops, also known as living mulches, have the capacity to improve soil quality, yet their effects on nitrogen (N) cycling and provisioning in organic systems are not well understood. We evaluated soil N contributions of kura clover (Trifolium ambiguum) between and within crop rows for four zone tillage approaches of varying intensity for corn (Zea mays). In 2015 and 2016, an established kura clover field was subjected to tillage treatments including no-till, traditional shank till, also known as strip-till (ST), novel, PTO-driven rotary zone till (ZT), and a combination of ST and ZT (DT; double till) in Rosemount, MN, followed by corn. An earlier planting date in 2015 (May 5, 2015 vs. May 18, 2016) contributed to a substantially lower rate of kura clover biomass at corn planting in 2015 (518 kg ha−1) compared to 2016 (3035 kg ha−1). The substantial difference in kura clover biomass contributions at tillage and planting between years appeared to govern N cycling indicators. For instance, soil inorganic N differed by tillage treatments only in 2016. After tillage, within row soil inorganic N was 68% and 106% greater than between rows for ST and DT treatments, respectively. At harvest, DT within row soil inorganic N was approximately double that of ST. We conclude that the N benefit from a legume living mulch depends on both the intensity of tillage and the amount of biomass present, and thus there may be advantages to delayed planting, particularly when used for organic production.

Rotary zone tillage improves corn establishment in a kura clover living mulch

Kura clover (Trifolium ambiguum Bieb.) perennial living mulch is a farming practice designed to pair water quality services and row crop production. In this system, rows are mechanically or chemically killed within a perennial kura clover stand to create a suitable environment for planting a crop. However, yields are often reduced relative to conventional, fully-tilled systems. This hypothesis was tested by using a novel rotary zone tillage unit (RZT) that creates 45 cm wide tilled strips with a depth of 8 cm for each row, with rows spaced 76 cm apart. We compared RZT to three row preparation strategies that have been commonly used in living mulch systems: herbicide band kill (BK), and shank tillage (ST), also known as strip tillage. Shank tillage produced bands that were 40 cm wide and 5 cm deep. We monitored kura clover health, soil moisture & temperature, corn (Zea mays L.) emergence, corn development, and corn yield in all three row preparation strategies over two growing seasons. In 2015, corn grown in RZT plots emerged and developed faster than corn grown in ST plots, but this did not lead to a difference in grain or stover yield. However, in 2016, corn grown in RZT plots not only emerged and developed faster, but also produced 4.0 Mg ha−1 more grain and 3.5 Mg ha−1 more stover biomass than corn grown in ST and BK plots. Kura clover biomass was not affected by treatment in either year. We conclude that rotary zone tillage is a promising row preparation strategy in kura clover living mulch for corn production with minimal herbicide use.

Soil carbon and nitrogen dynamics under zone tillage of varying intensities in a kura clover living mulch system

Zone tillage is a reduced-tillage approach that attempts to capture both the environmental advantages of year-round ground cover and the agronomic benefits of in-row tillage. This study was conducted to determine the effect of differing levels of zone tillage intensity on soil carbon and nitrogen cycling in a corn-kura clover cropping system (Zea maize-Trifolium ambiguum). Research took place in Rosemount, MN in 2015 and 2016 in an established kura clover stand. Soils and kura clover biomass were each sampled three times in crop rows per year in four treatments that varied by intensity: NT (spray-down no-till), ST (shank-till, traditional strip till unit), RZT (zone-till, PTO-driven rotary zone tiller), and DT (double-till, ST + RZT). Samples were analyzed for microbial biomass (MB), soil inorganic nitrogen, and permanganate oxidizable carbon (POXC). Additionally, potentially mineralizable nitrogen (PMN) was measured for 2016 post-spring tillage soils. Greater spring kura clover biomass in 2016 (2449 kg ha−1) relative to 2015 (187 kg ha−1) influenced overall differences in soil quality between years. The double-till (DT) treatment had greater post-till soil inorganic N than the no-till (NT) treatment in 2016, and by corn harvest, both zone-till (RZT) and double-till (DT) had higher soil inorganic N than NT, indicating that the addition of kura clover biomass contributed to in-row, plant-available nitrogen. Double-till was also more effective in reducing kura clover encroachment into crop rows than NT. No effect of tillage intensity on PMN, MB, or POXC was observed at any sampling time, although trends of decreasing POXC paired with increasing MB over the 2016 growing season suggest that the quantity of incorporated kura clover biomass may have governed belowground nutrient cycling and soil fertility.

New insights on speleoseismology: The geothermal gradient and heat flow values in caves for the study of active faults

Normally in paleoseismology, the study of the tectonic slip-rate is performed in trenches on the fault scarp, or by the estimation of fault movements from the geomorphic features. In this work, we have carried out a paleoseismic analysis of the Benis Fault, located in southeast Spain, combined with a geothermal analysis inside a deep cave related to the fault (−350 m). Thus, we have estimated the last earthquake magnitude and time of occurrence from evidence of ceiling collapse and displaced carbonate blocks inside a cave, which is developed across the fault. The magnitude was obtained from the application of the empirical relationship of the fault parameters and coseismic vertical displacement, yielding a value ranging between M 5.9 and M 6.5. Moreover, we dated this paleoearthquake by the paleontological record of a “Lynx pardinus spelaea”, with an age of 65 ± 18 ka BP. Additionally, we have measured the thermal profile of the Benis Cave (−350 m of depth), from single rock point temperature measurements during 2 years. The temperature profile shows three different parts inside the cave, the shallow heterogeneous thermal zone till 50 m depth; the homogeneous thermal zone 150 m till with constant temperature and the hetero-thermal deep zone, deeper than 150 m and till the deepest zone (350 m). Furthermore, we have estimated the Vertical Geothermal Gradient, 1.85 °C/100 m for the deepest zone (−150; −290 m). The temperature increases with depth, showing a reverse thermal profile in comparison with normal gradients in deep caves. Finally, we have calculated the heat flux of 0.46 mWm2.

Evaluating the use of permanent beds for growing vegetables in North Queensland

Systems for vegetable production in the dry tropics of North Queensland, Australia, have been dominated by intensive tillage and extensive use of nonrenewable polyethylene inputs. A field trial was established to investigate agronomic practices and soil health changes in capsicum and zucchini crops grown with intensive tillage and permanent bed systems. In 2011, conventional intensive tillage with 'plasticulture' was compared to a permanent bed system with subsurface drip irrigation, no soil disturbance and organic mulch produced from a summer sorghum crop. Soil compaction was a major production constraint in the permanent beds in 2011, along with water and nutrient management. Compared to intensive tillage, marketable yield in permanent beds had reductions of 70 and 30%, respectively in capsicum and zucchini. In 2012, the same intensive tillage system was compared to a permanent bed system where minimal soil disturbance had been produced by zone tillage in 10% of the cropped area. It was also compared to a modified system which had permanent beds and zone till but, in addition, had a polyethylene film mulch over the planting beds. The zone tillage and improved fertigation management in 2012 led to marketable yields that were not significantly different among the three tillage systems. In 2013, crops in permanent beds covered with a biodegradable film instead of polyethylene film, had marketable yields that were comparable to the intensive tillage system. Results from the first three years of this study gave indication that minimum tillage has the potential to provide acceptable marketable yields with less dependence on polyethylene use.

Facile preparation and characterization of poly(vinyl alcohol)/chitosan/graphene oxide biocomposite nanofibers

Poly(vinyl alcohol) (PVA)/chitosan (CS)/graphene oxide (GO) biocomposite nanofibers have been successfully prepared using aqueous solution by electrospinning. CS colloidal gel in 1% acetic acid can be changed to homogeneous solution by using electron beam irradiation (EBI). The uniform distributions of GO sheets in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and Raman spectroscopy. FESEM images illustrated that the spread single GO sheet embedding into nanofibers was formed via self-assembly of GO sheet and PVA/CS chains. And the average diameters of the biocomposite nanofibers decreased (200, 173, 160 and 123nm) with increasing the contents of GO (0.05, 0.2, 0.4 and 0.6wt%). Raman spectra verified the presence of GO in the biocomposite nanofibrous mats. The mechanical properties of as-prepared materials related with GO contents. It revealed that the highest tensile strength was 2.78MPa, which was 25% higher than that of neat PVA/CS nanofibers. Antibacterial test demonstrated that the addition of GO to PVA/CS nanofiber had great ability to increase inhibition zone till 8.6mm. Overall, these features of PVA/CS/GO nanofibers which were prepared by eco-friendly solvent can be a promising candidate material in tissue engineering, wound healing and drug delivery system.

羊草草地对原地放垡振动间隔松土的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 羊草草地对原地放垡振动间隔松土的响应 DOI: 10.5846/stxb201401110081 作者: 作者单位: 贵州大学动物科学学院,贵州大学动物科学学院,贵州大学动物科学学院,天津市畜牧兽医研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（31101751）；贵州省科技厅项目（黔科合NY字[2012]3011号，黔科合J字[2011]2325号） Response of Leymus Chinensis grassland to situ-vibration scarifying technique Author: Affiliation: Guizhou University,Guizhou University,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以虚实并存耕作理论为指导，运用原地放垡振动间隔松土技术，采用野外观测、实地取样与室内分析相结合的方法研究了原地放垡振动间隔松土对羊草草地的改良效果。结果表明，原地放垡振动间隔松土提高了羊草草地植物高度、盖度、生物量和多样性，增加了优良类牧草所占比例和载畜力；运用原地放垡振动间隔松土技术改良羊草草地使每公顷草地植物生产层平均每年增加直接经济收益为1119.0元，动物生产层增加直接经济收益2142.0元，前植物生产层潜在（固碳）经济效益为219.5元。通过样地监测和分析可以得出，原地放垡振动间隔松土措施适用于大面积改良羊草草地和其它优质高产的根茎型草地。 Abstract:Leymus Chinensis grassland is one of the major types in the Eurasian steppe region, however, Leymus Chinensis grassland is in heavy degradation, for example, soil compacted, good kinds of grass decreased, etc. which is owing to lack of good management for long time. So expert of China Agriculture University developed situ-vibration scarifying machine which is based on zone tillage theory, and the machine was applied to reform Leymus Chinensis grassland in 2007. Then, in year of 2009 and 2012, field observation, sampling and laboratory analysis were used to analyze the effects. The results showed that application of situ-vibration scarifying technique on Leymus Chinensis grassland improved the vegetation height, coverage, biomass and biodiversity, increased the proportion of good pasture and the animal carrying capacity. The method increased farmer's income, including 1119.0 Yuan hm-2 a-1 in plant production layer, or 2142.0 Yuan hm-2 a-1 in animal production layer, and 219.5 Yuan hm-2 a-1 in potential economic benefit (that is carbon sequestration). Through monitoring and analysis, it can be drawn that the situ-vibration scarifying technique is suitable for improve Leymus Chinensis grassland or other high-quality rhizome grasslands. 参考文献 相似文献 引证文献

Nitrogen Source, Application Time, and Tillage Effects on Soil Nitrous Oxide Emissions and Corn Grain Yields

A 3-yr study was conducted to determine the effectiveness of N fertilizer application times (at planting vs. sidedress) and N fertilizer source (regular urea vs. coated urea) on N2O emissions and corn (Zea mays L.) grain yields from soil under conventional tillage (CT), zone tillage (ZT), or no-tillage (NT) in southwestern Ontario. On average, 4.19 kg N ha−1 yr−1 were lost from the CT treatments as N2O and these losses were reduced by 16.6% with NT (3.50 kg N ha−1 yr−1) and by 43.8% with ZT (2.35 kg N ha−1). There were some significant effects of N source and application time on N2O emissions; however, these were inconsistent among tillage treatments and years. In 2004, there was a significant interaction between N source and tillage with regular urea (6.49 kg N ha−1) producing 2.7 times more N2O than coated urea (2.40 kg N ha−1) with CT. However, N source did not significantly affect N2O emissions in either 2005 or 2006. In CT treatments, the 3-yr average N2O emissions using N applied at planting (5.02 kg N ha−1 yr−1) were, on average, 49% greater than when sidedress urea (3.37 kg N ha−1 yr−1) was applied. The 3-yr average corn grain yield for CT (9.38 t ha−1) was significantly greater than for NT (8.35 t ha−1), while the yield for ZT (9.01 t ha−1) was not significantly different from either CT or NT. The influence of tillage, N application time and N source on N2O emissions and corn grain yields appeared to be partially related to the amount and timing of precipitation and the root zone soil moisture content. Polymer-coated urea was most effective in 2004 under CT when the soil moisture was high in the first month after planting due to antecedent soil moisture conditions and rainfall. Under these wetter conditions, N2O emissions were reduced by either delaying urea hydrolysis with polymer-coated urea or by using ZT instead of CT.