Traffic and tillage effects on soil health and crop growth

The growing world population demands rise of crop yields, which has resulted in agricultural intensification. This in turn has been accompanied by an increase in machinery size and weight, escalating degrees of soil compaction and has led to soil degradation of an area of 33 million ha in Europe. Compacted soil inhibits root development, water availability, nutrient uptake and causes yield loses. Remedial actions are expensive, and time consuming and require burning additional fossil fuels. Climate change is one of the most urgent problem and requires more sustainable approach to food production. Reducing fossil fuel consumption, whilst maintaining the soil in a good condition to facilitate water infiltration and carbon sequestration resulting from improved root development is of great importance. This thesis reports on a three-year study conducted within a unique long-term 3x3 factorial experiment with four replicates, which started at Harper Adams University (UK) in October 2011. This study quantified the effects of absence of traffic (CTFut) vs traffic with standard and low tyre inflation pressure (STP and LTP respectively), influenced by different tillage depths (deep–250mm, shallow–100mm and zero–tillage) on soil physico-chemical and biological properties, as well as on crop growth and yields. Additionally, it investigated the effect of three common farming traffic systems: Controlled Traffic Farming with 30% of trafficked area (CTF), and two random traffic systems: with standard and low inflation pressure tyres (RSTP and RLTP) subject to three tillage depths (deep, shallow and zero) on plant establishment and combine harvested yields. The analysed soil physico-chemical properties were: soil bulk density, porosity, penetration resistance, moisture content, field saturated hydraulic conductivity and instant infiltration rate, soil microbial carbon, soil organic matter and pH. The soil biological properties included soil fauna feeding activity, Collembola and earthworm abundance. The crop growth indicators included plant establishment, root growth and hand harvested and combine harvested yield. The results from this study demonstrated that agricultural traffic, regardless tyre inflation pressure, had significant negative effects on soil physico-chemical and biological properties in comparison to unwheeled soil. The untrafficked soil (CTFut) featured significantly lower soil bulk density and penetration resistance, at the same time, significantly improved soil porosity, field saturated hydraulic conductivity and instant infiltration rate in comparison to soil trafficked with standard and low inflation pressure tyres (STP and LTP respectively). The absence of traffic also significantly improved soil biological properties namely soil fauna feeding activity, and Collembola abundance in 24 comparison to STP and LTP. The plant establishment and root growth were also significantly enhanced under untrafficked soil (CTFut) vs STP and LTP. All these improvements in soil physico-chemical and biological properties led to the combine harvested yield increase by 4% under CTF system which in the experiment had 30% of trafficked area. This can be recalculated to additional 3% increase for CTF with 15% of trafficked area. Consequently, the adoption of CTF which restricts farming traffic to permanent wheelways covering in farming practice approximately 12-15% of the field area, brings significant improvements in soil physico-chemical and biological properties and as a result, it enhances crop growth and yield in comparison to non-controlled traffic systems (RSTP and RLTP) under which the majority of the field area is covered by at least one wheel pass every year. The main effects of tyre pressures did not have a significant effect on soil physicochemical properties. Nevertheless, LTP significantly improved soil fauna feeding activity (FA) in comparison to standard tyres pressures (STP). Interactions between traffic system and tillage depth revealed that RLTP increased combine harvested yields on deeply tilled soils in comparison to RSTP (104% on average over the 8-year study). The main effect of tillage and the interactions between traffic and tillage were not significant for soil physico-chemical characteristics. Tillage had however significant effects on soil biological properties. Nevertheless, the results do not conclusively indicate one tillage depth which could improve soil biology, as the SOM and similarly earthworms abundance were significantly greater under zero and shallow tillage than under deep tillage, however soil fauna feeding activity in 2019 on zero tillage was significantly lower than on remaining tilled treatments, similarly the Collembola density was significantly lower under zero tillage in comparison to shallow tillage, whereas deep tillage did not differ significantly from the remaining tillage depths. Nevertheless, in 2020 both reduced tillage treatments (zero and shallow tillage) featured significantly greater FA than deep tillage. Interactions between tillage and time revealed that with time, under zero tillage, the crop yields improve and, in the year 7th and 8th yields from zero tillage were significantly greater than from deep tillage (105% and 103% in 2019 and 102% and 112% in 2020 respectively). There was no single aspect of soil physico-chemical and biological properties, as well as crop growth and yields, which would indicate that deep tillage provided better results over 25 shallow tillage, which might suggest that deep tillage is not a recommended practice on sandy loam in West Midlands, UK. This leads to a conclusion that the optimal mechanisation system’s approach (combination of traffic system and tillage depth) consists of CTF with shallow tillage; alternatively, zero tillage system, which is more resilient to agricultural traffic, with the caveat of yields penalties in the first years. The use of low inflation pressure tyres (LTP) is recommended, should deep tillage be required without CTF, as they reduce the impact of compaction and improve the crop yield. This thesis also outlines additional environmental consequences, which in further studies might be developed in a robust environmental economics of traffic and tillage systems

Controlled traffic farming delivers better crop yield of winter bean as a result of improved root development

This paper reports on the continuation of a long–term experiment on the effects of alternative field traffic systems (STP–random traffic with standard tyre inflation pressure, LTP–random traffic with low tyre inflation pressure and CTF–controlled traffic farming) on soil conditions and crop development as influenced by different tillage depths (DEEP–250 mm, SHALLOW–100 mm and ZERO–tillage), in a randomised 3 x 3 factorial design in 4 replicates launched by Harper Adams University in Edgmond, UK, in 2011. The results from season 2017–2018 revealed that CTF delivered 8% higher crop yield of winter field bean (Vicia faba) cv. Tundracomparing to STP (p = 0.005), i.e. 4.13 vs 3.82 tonnes ha-1respectively (at 14% moisture content). The ZERO–tillage plots featured significantly lower plant establishment percentage comparing to shallow and deep tillage: 79% vs 83% and 83% respectively (p = 0.012). The research showed that roots traits differed significantly between contrasting traffic at depths greater than 50mm with p < 0.05of: tap root biomass, number of lateral roots, biomass of lateral roots as well as total root biomass (tap+lateral roots),delivering significantly greater values of those before mentioned parameters on CTF comparing to STP. Tap root length significantly differed between traffic systems (p < 0.001)giving significantly greater results on CTF comparing to LTP and STP (17.7, 13.4 and 12.6 mm respectively). Significant differences in tap root diameter were found only at the depth of 100 mm (p < 0.001) where again CTF delivered significantly higher root diameter than the remaining 2 traffic systems.In the shallow layer of soil (0–50 mm) a significant difference was found only for tap root biomass, for interactions, where STP ZERO gave significantly higher results than STP SHALLOW and CTF SHALLOW (1.430, 0.733 and 0.716 g respectively)

Characterization of Polyphosphoesters by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

FT-ICR mass spectrometry, together with collision-induced dissociation and electron capture dissociation, has been used to characterize the polyphosphoester poly[1,4-bis(hydroxyethyl)terephthalate-alt-ethyloxyphosphate] and its degradation products. Three degradation pathways were elucidated: hydrolysis of the phosphate–[1,4-bis(hydroxyethyl)terephthalate]bonds; hydrolysis of the phosphate–ethoxy bonds; and hydrolysis of the ethyl–terephthalate bonds. The dominant degradation reactions were those that involved the phosphate groups. This work constitutes the first application of mass spectrometry to the characterization of polyphosphoesters and demonstrates the suitability of high mass accuracy FT-ICR mass spectrometry, with CID and ECD, for the structural analysis of polyphosphoesters and their degradation products

The application of allelopathy in integrated pest management systems to control temperate European crop pests: a systematic map

Background Pesticides perform vital roles within agriculture but growing concern for their impact on the environment and non-target organisms has created a market for biopesticides with fewer ecological impacts. One source of biopesticides is allelochemicals, here defined as compounds released by an organism that have an inhibitory or stimulatory effect on neighbouring organisms. The focus of this study is allelopathic plants and their inhibitory effects on invertebrate herbivorous agricultural pests of temperate Europe. A systematic map is required to describe the current state of research and collate evidence. Methods Two academic databases were searched for relevant studies in temperate climates. The results were imported into EPPI-Reviewer, duplicates removed, studies screened and data extracted into a searchable database following the inclusion criteria and coding tool set out in the protocol. Screening consistency was checked at each stage using 5% of the studies. Critical appraisal was not conducted. Each unique combination of key variables (pest, plant, allelochemical, application method, intervention form) was treated as a separate datapoint or experiment. The data was then analysed and cross-tabulated to produce descriptive statistics and heatmaps. Results This systematic map produced a database which included 243 studies containing 717 experiments from 5550 initial results. Research was unevenly distributed among all key variables with a distinct bias towards extracted allelochemical experiments under laboratory conditions. Allyl isothiocyanate was the most studied allelochemical and of the 99 identified chemical groups, flavonoids and glucosinolates were the most frequent. A wide range of pest and plant species were identified. Brassicas were the most studied plant family and Lepidoptera the most studied pest order. Physical living plants, as opposed to plant extracts or isolated allelochemicals, were predominantly studied in terms of resistance. Allelopathy application methods were not specified in the abstract of 22% of experiments and only 10% of experiments were conducted under field conditions. Conclusion Allelopathy has been studied in the context of temperate invertebrate pest control in some breadth but little depth and key pest species have not been targeted. The map highlighted significant gaps in the evidence base and a distinct lack of field studies or studies comparing application methods. It contains insufficient evidence to guide policy or management decisions, but provides a research tool and indicates areas for future studies including highlighting topics for secondary research. Critical appraisal is needed to determine allelopathic affect and future search strings should detail all application methods

In vitro and in vivo assessment of the potential of escherichia coli phages to treat infections and survive gastric conditions

Enterotoxigenic Escherichia coli (ETEC) and Shigella ssp. infections are associated with high rates of mortality, especially in infants in developing countries. Due to increasing levels of global antibiotic resistance exhibited by many pathogenic organisms, alternative strategies to combat such infections are urgently required. In this study, we evaluated the stability of five coliphages (four Myoviridae and one Siphoviridae phage) over a range of pH conditions and in simulated gastric conditions. The Myoviridae phages were stable across the range of pH 2 to 7, while the Siphoviridae phage, JK16, exhibited higher sensitivity to low pH. A composite mixture of these five phages was tested in vivo in a Galleria mellonella model. The obtained data clearly shows potential in treating E. coli infections prophylactically

Agricultural traffic management systems and soil health

This chapter examines the relationship between agricultural traffic and soil compaction. It begins by reviewing research on how agricultural traffic affects soil compaction as well as ways of measuring soil compaction and its effects. It then discusses a range of potential techniques to avoid soil compaction. These include: controlled-traffic farming, low ground pressure tyre systems as well as tracks and gantry systems. The chapter also discusses the relationship between different tillage practices and soil compaction. It includes a case study based on research conducted by the authors

The effects of traffic management systems on the yield and economics of crops grown in deep, shallow and zero tilled sandy loam soil over eight years.

This paper reports on a 3 × 3 factorial study to consider the effects of controlled traffic (CTF), low tyre inflation pressure (high flexion) tyres (LTP) and standard tyre inflation pressure (STP) farming systems for deep, shallow and zero tillage practices on the yield of wheat, barley, oats and field beans grown in a sandy loam soil in the UK. The main effect of tillage showed that the zero tillage option significantly (***P < 0.001) reduced crop yields in four out of the five of the first crop years, with no significant effect in years two, six and eight and exceeded the yield of the other tillage treatments in year seven. The specific costs of the alternative tillage systems were estimated, from which the cost saving for zero tillage compared to deep tillage was c. £ 60 ha−1 (US$80 ha−1), which compensated for the overall loss in yield. There were no significant differences between the crop yields from the deep and shallow tillage treatments, with shallow tillage offering savings in operational costs of c. £ 30 ha−1 (US$ 40 ha−1). Overall, the controlled traffic farming system, where 30% of the field was trafficked, produced 4% greater crop yields (*P < 0.05), worth £ 39 ha−1 (US$53 ha−1) than standard tyre inflation pressures (STP). The estimated effect of reducing the trafficked area to 15$ 100 ha−1) compared to the STP system. The beneficial effect of low inflation pressure tyres (70 kPa and 80 kPa) on crop yields, for the deep tillage treatment, was significantly greater (*P < 0.05) than those of the standard tyre pressure system (100 kPa to 150 kPa) returning an average 3.9% additional crop yield over the period of the experiment worth £ 39 ha−1 (US$ 53 ha−1)

Genotypic and phenotypic spectrum of pyridoxine-dependent epilepsy (ALDH7A1 deficiency)

Pyridoxine-dependent epilepsy was recently shown to be due to mutations in the ALDH7A1 gene, which encodes antiquitin, an enzyme that catalyses the nicotinamide adenine dinucleotide-dependent dehydrogenation of L-{alpha}-aminoadipic semialdehyde/L-{Delta}1-piperideine 6-carboxylate. However, whilst this is a highly treatable disorder, there is general uncertainty about when to consider this diagnosis and how to test for it. This study aimed to evaluate the use of measurement of urine L-{alpha}-aminoadipic semialdehyde/creatinine ratio and mutation analysis of ALDH7A1 (antiquitin) in investigation of patients with suspected or clinically proven pyridoxine-dependent epilepsy and to characterize further the phenotypic spectrum of antiquitin deficiency. Urinary L-{alpha}-aminoadipic semialdehyde concentration was determined by liquid chromatography tandem mass spectrometry. When this was above the normal range, DNA sequencing of the ALDH7A1 gene was performed. Clinicians were asked to complete questionnaires on clinical, biochemical, magnetic resonance imaging and electroencephalography features of patients. The clinical spectrum of antiquitin deficiency extended from ventriculomegaly detected on foetal ultrasound, through abnormal foetal movements and a multisystem neonatal disorder, to the onset of seizures and autistic features after the first year of life. Our relatively large series suggested that clinical diagnosis of pyridoxine dependent epilepsy can be challenging because: (i) there may be some response to antiepileptic drugs; (ii) in infants with multisystem pathology, the response to pyridoxine may not be instant and obvious; and (iii) structural brain abnormalities may co-exist and be considered sufficient cause of epilepsy, whereas the fits may be a consequence of antiquitin deficiency and are then responsive to pyridoxine. These findings support the use of biochemical and DNA tests for antiquitin deficiency and a clinical trial of pyridoxine in infants and children with epilepsy across a broad range of clinical scenarios

Design and synthesis of new quinazolin-4-one derivatives with negative mGlu7mGlu_7 receptor modulation activity and antipsychotic-like properties

Following the glutamatergic theory of schizophrenia and based on our previous study regarding the antipsychotic-like activity of mGlu7 NAMs, we synthesized a new compound library containing 103 members, which were examined for NAM mGlu7 activity in the T-REx 293 cell line expressing a recombinant human mGlu7 receptor. Out of the twenty-two scaffolds examined, active compounds were found only within the quinazolinone chemotype. 2-(2-Chlorophenyl)-6-(2,3-dimethoxyphenyl)-3-methylquinazolin-4(3H)-one (A9-7, ALX-171, mGlu7 IC50 = 6.14 &micro;M) was selective over other group III mGlu receptors (mGlu4 and mGlu8), exhibited satisfactory drug-like properties in preliminary DMPK profiling, and was further tested in animal models of antipsychotic-like activity, assessing the positive, negative, and cognitive symptoms. ALX-171 reversed DOI-induced head twitches and MK-801-induced disruptions of social interactions or cognition in the novel object recognition test and spatial delayed alternation test. On the other hand, the efficacy of the compound was not observed in the MK-801-induced hyperactivity test or prepulse inhibition. In summary, the observed antipsychotic activity profile of ALX-171 justifies the further development of the group of quinazolin-4-one derivatives in the search for a new drug candidate for schizophrenia treatment