Normal Ploughing Research Articles

Effect of tillage and land levelling practices on productivity of transplanted rice: A case study in canal command area of north western plateau agro-climatic zone

An on-farm study on the response of transplanted rice to land preparation methods was undertaken on a sandy clay loam soil in Pitamahal irrigation command of Sundargarh district (Odisha) for two consecutive dry seasons of 2019-20 and 2020-21. The treatments included normal ploughing with desi plough followed by levelling of 0.5 – 1 % slope (T1), deep ploughing (20 - 25 cm) with bullock drawn M.B. plough followed by levelling of 0 - 0.25 % slope (T2), and farmers' practice of ploughing with desi plough and levelling varying 1-3 % slope (T3) for puddling operation. Deep ploughing (T2) resulted in higher root length (23.88 cm) and root 3 volume (81.75 cm ), owing to the initial rapid growth of roots promoted by deep ploughing that cracked the hardpan. This also increased the movement of water both laterally and vertically (7.44 mm per day) compared to T1 and T3's 5.11 and 5.71 m per day, respectively. The treatment also resulted in a significantly greater grain yield -1 (45.90 q ha ) due to a much larger effective tiller m-2 (423.40) and number of grains per panicle (71.80), as well as a higher net return per rupee spent (7.54) and benefitcost ratio (2.01).

Comparative effects of partial conservation farming practices on plant development and yield

Sustainable farming systems are being introduced to ensure optimum agricultural productivity despite climate change and environmental degradation. One such sustainable agricultural technology is conservation farming (CF). The uptake of this technology has remained low at about 5% years after its introduction. CF has five interrelated practices but for a variety of reasons, farmers are unable or unwilling to adopt all recommended practices. This study studied the agronomic effects of incomplete or partial conservation practice whereby not all the five practices are used, mimicking actual practices adopted by farmers. A split- plot design experiment involving partial or incomplete CF mainly use of basins, ripping were compared to conventional farming of normal ploughing (as main plots) and three crops - cowpea, millet and sorghum (split plot) was conducted. The objective was to determine the agronomic effects and efficacy of partial adoption of CF compared to conventional farming system. Data were collected on vegetative and reproductive parameters including, plant height, germination percentage, canopy density, number of leaves, number of branches/tillers/stems, SPAD (Soil Plant Analysis Development) readings a proxy for leaf chlorophyll content. Plants grown in basins had higher plant development (plant height, total biomass) and higher yields compared to those on conventional methods. This effect could be explained by better soil physical and chemical conditions in the basins as indicated by higher SPAD readings. Int. J. Agril. Res. Innov. Tech. 12(1): 115-119, June 2022

Prediction of Nonlinear Micro-Milling Force with a Novel Minimum Uncut Chip Thickness Model.

The minimum uncut chip thickness (MUCT), dividing the cutting zone into the shear region and the ploughing region, has a strong nonlinear effect on the cutting force of micro-milling. Determining the MUCT value is fundamental in order to predict the micro-milling force. In this study, based on the assumption that the normal shear force and the normal ploughing force are equivalent at the MUCT point, a novel analytical MUCT model considering the comprehensive effect of shear stress, friction angle, ploughing coefficient and cutting-edge radius is constructed to determine the MUCT. Nonlinear piecewise cutting force coefficient functions with the novel MUCT as the break point are constructed to represent the distribution of the shear/ploughing force under the effect of the minimum uncut chip thickness. By integrating the cutting force coefficient function, the nonlinear micro-milling force is predicted. Theoretical analysis shows that the nonlinear cutting force coefficient function embedded with the novel MUCT is absolutely integrable, making the micro-milling force model more stable and accurate than the conventional models. Moreover, by considering different factors in the MUCT model, the proposed micro-milling force model is more flexible than the traditional models. Micro-milling experiments under different cutting conditions have verified the efficiency and improvement of the proposed micro-milling force model.

Influence of cultivation methods on suspended solids and phosphorus concentrations in surface runoff on clayey sloped fields in boreal climate

Abstract Methods for decreasing agricultural phosphorus (P) loadings to surface waters are needed to achieve good water quality. To reliably find out the efficiency of different methods in changing hydrological conditions, long-term experiments are of invaluable importance. Here the effects of various cultivation methods on total suspended solids (TSS) and P concentrations in – and the volume of – plough layer runoff (PLR) were studied in a sloping experimental field in southwest Finland during a 9-year period. Yearly means of PLR and flow-weighted mean concentrations from the treatment plots were compared with a control, winter wheat ( Triticum aestivum ) treatment (WW), of which the values assigned were equal to 1. No major differences were found in PLR for cultivation methods up and down slope, except for the cross-ploughing treatment (0.49). Normal ploughing and cultivation treatments produced the highest TSS concentrations (1.38 and 1.18, respectively), whereas values between 0.44 and 0.53 were measured for three treatments with reduced (or no) tillage. Particle-bound P (PP) concentrations closely followed those of TSS. Dissolved reactive P (DRP) showed contrasting behaviour, with the greatest treatment effects from the three reduced tillage treatments (1.58–2.29). This study showed that by changing over from intensive autumn tillage to permanent vegetation cover, erosion and PP loss were markedly decreased. Methods employing no autumn tillage and leaving an undisturbed soil surface during winter showed particularly high reductions in loading. The simultaneous increase in DRP loss is an undeniable drawback that should be resolved separately. This study, as a part of a wider complex of integrated studies, will be utilized in a decision-making tool for the assessments of loading effects and load reduction possibilities in terms of cultivation methods.

Effect of fertilizers and tillage management in rice (Oryza sativa)-chickpea (Cicer arietinum) cropping system under varying irrigation schedules

A field experiment was carried out during 2000-01 and 2001-02 at the Indian Institute of Pulses Research, Kanpur, to study the effect of fertilizers, tillage and irrigation management in chickpea (Cicerarietinum L.) raised after rice (Oryza sativa L.). Significantly higher growth and yield attributes of chickpea were obtained under- treatment 30:60:40 kg NPWha, deep ploughing with spade (23 cm deep) and cumulative pan evaporation (CPE) of 60 mm compared to 20:40:40 kg NPWha, normal ploughing and CPE of 80 rnrn. Significantly higher grain and straw yield of chickpea, chickpea-equivalent yield and monetary returns were obtained with 30:60:40 kg NPWha than 20:40:40 kg NPWha. Among the various tillage practices, deep ploughing with spade (23 cm deep) re- corded significantly higher grain and straw yields of chickpea, chickpea-equivalent yield and economics than normal ploughing. Significantly higher productivity and monetary returns of chickpea was obtained at CPE of 80 mm compared to CPE of 80 mm. The NPK uptake by rice and chickpea and total uptake by the system were sig- nificantly higher under CPE of 60 mm, deep tillage and 30:60:40 kg NPWha than CPE of 80 mm, normal tillage and 20:40:40 kg NPWha. Bulk density, particle density, water-holding capacity, pore space and volume expan- sion of soil were greatly influenced by different tillage and nutrients management. The residual effect of nutrients management and tillage practices applied during the winter (rabo season was also seen in the preceding crop of rice in second year.

Control of nitrate leaching from a Nitrate Vulnerable Zone using paper mill waste

Abstract. The effects on nitrate leaching of incorporation of paper mill waste at three cultivation depths in fields previously cropped to iceberg lettuce and calabrese are reported. In the lettuce experiment, incorporation of 40 t DM paper mill waste/ha resulted in a decrease in N leaching (measured with suction cups) from 177 to 94 kg/ha (S.E.d= 23). Deep ploughing with and without paper waste increased N leaching from 105 kg/ha (normal ploughing or surface incorporation) to 172 kg/ha (S. E. d= 27). Measurements of nitrate leaching using deep soil cores showed a less clear cut effect. Nitrous oxide (N2O) emissions were very high immediately after paper waste was ploughed in to a depth of 35 cm. Non–significant increases in biomass N content were measured in the spring following paper waste application. There was no significant reduction in plant N uptake in subsequent crops. Removal of above–ground crop residues did not have a significant effect on nitrate leaching or N2O losses. In the calabrese experiment, application of 40 t DM paper mill waste/ha followed by summer cropping with iceberg lettuce caused a decrease in N leaching (measured using deep soil cores) from 227 to 152 kg/ha (S. E.d= 22, mean of all cultivation treatments).

Carabid Beetles and Agricultural Practices: Influence of Soil Ploughing

ABSTRACT Deep ploughing drastically changes soil structure and is probably one of the most disturbing agricultural practices for soil fauna. The aim of this paper was to investigate the effect of ploughing reduction on the structure and composition of adult carabid beetle communities. Three soil treatments, normal ploughing, light ploughing and no ploughing, were applied in four kinds of crop. Carabid beetles were sampled weekly using pitfall traps. Soil ploughing increases the abundance of the dominant species, Pterostichus melanarius. Species richness significantly depended on the crop type. However, it appears that the less abundant species in deep ploughing became more numerous when reduced tillage or no cultivation was applied.

Soil-structure differences and associated physical properties of some loamy typic fluvaquents in The Netherlands

Three soil-structure types could be distinguished with macro- and micro-morphological techniques in an important Dutch mapping unit (Mn15A: Typic Fluvaquent). The soil-structure types were associated with land use (pasture and arable land) and management (normal ploughing and deep tillage for arable land). Soil-structure observations in the field, combined with penetrometer readings, p permit identification of each of these structure types, which are associated with significantly different hydraulic-conductivities and moisture-retention data, measured at least 4-fold for each structure type. Rooting patterns were also significantly different. The observed differences in physical data among soil-structure types within the mapping unit do not allow use of this unit itself as a “carrier” of physical information. Recognition of the separate soil-structure types, however, permits estimation of hydraulic-conductivityand moisture-retention data for all soils within the mapping unit considered. Tis is necessary for farm-scale applications.

Terramechanics research in the Soil Section of the Scottish Institute of Agricultural Engineering

This is a documentary article describing the Institute's work concerning terramechanics. A brief history of the Soil Section outlines its purpose in relating the characteristics of agricultural machinery, the physical properties of soils and crop growth behaviour. The facilities of the Soil Section are described and its success in developing a high-resolution gamma-ray probe to measure soil bulk density and a recording penetrometer is described. Soil compaction measurements have been carried out for alternatives to the conventional tractor wheel and use of a drop-cone to measure soil plastic limit has been developed. Current efforts are focused on performance measurements of multiple-wheel configurations, four-wheel-drive tractors, consideration of soil compaction under modern crawler tracks and research on the effects on crop yield of soil loosening below normal ploughing depth. Development of prediction models for soil compaction is a major interest.

The effect on earthworms of ploughing, tined cultivation, direct drilling and nitrogen in a barley monoculture system

SUMMARYDilute formalin was used to sample earthworm populations after the second (1969) and sixth (1973) harvests from a continuous barley experiment in which the cultivation treatments include deep (30 cm), normal ploughing (20 cm) and tined (three passes to 20 cm) cultivations and no tillage (direct drilling), at four nitrogen rates: 0, 50, 100 and 150 kgN/ha. Eight species of Lumbricidae were found, withAllolobophora chloroticaandA. longaco-dominant in both years, joined byA. caliginosain 1973.In 1969,Lumbricusspp., particularly largeLumbricus terreslris, tended to be more numerous in the untilled plots.In 1973, the total populations had increased by 170%, with 50–100% more earthworms in untilled than ploughed plots, one third more with 50 and 100 kg N/ha fertilizer than with no nitrogen, and one-third more in the slightly heavier sandy clay loam soil than the lighter loam.Most earthworm species reacted in the same way, and the reasons for any unusual reactions are discussed.

THE EFFECTS OF TILLAGE, DIRECT DRILLING AND NITROGEN FERTILISER ON SOIL TEMPERATURE UNDER A BARLEY CROP

SummaryContinuous hourly records of soil temperature were collected at 1, 5 and 20 cm, throughout two growing seasons, 1973 and 1974, under crops of spring barley in the east of Scotland. Measurements were obtained from three cultivation treatments, deep ploughing, normal ploughing and direct drilling, at two nitrogen fertiliser levels, 0 and 150kg/ha. Compared with ploughed soil, direct‐drilled soil had a higher surface reflection coefficient and a higher thermal diffusivity between 5 and 20 cm; overall, this resulted in lower heat sums (°C hours/day over 5 °C and 10 °C) in direct‐drilled soil at 1 cm and 5 cm during the first 20 days after sowing. The thermal regimes of normally and deeply ploughed plots were very similar. Nitrogen fertiliser caused significant lowering of soil temperature at all three depths in the latter half of the growing season, due to increased shading of the soil surface by the crop canopy. Some implications of these findings for cultivations for cereals are discussed.

Effects of tillage and direct drilling on soil properties during the growing season in a long-term barley mono-culture system

SUMMARYSoil responses to deep (30–35 cm) and normal (15–20 cm) mouldboard ploughing, chisel ploughing and zero-tillage have been compared for 7 years in a field experiment growing continuous spring barley near Edinburgh. The soil was of variable texture, from moderately well-drained sandy loam overlying loam to imperfectly to poorly drained sandy clay loam overlying clay loam, classified as stagnogleyic brown earth to cambio stagnogley soil. Soils of this type derived from Carboniferous till are widely used for cereal production in south-east Scotland. Measurements of soil physical properties were made at crop emergence, midseason and at harvest to characterize seasonal and long-term responses to tillage and traffic. After the first 3 years bulk density responses varied little within or between seasons, showing a compacted horizon from 0–15 cm under zero-tillage and a looser horizon from 21–33 cm under deep ploughing compared with normal ploughing. Immediately below the depth of normal ploughing there was no difference in bulk density between this treatment and zero-tillage while in some years the chisel-ploughing treatment was denser. Moisture content responses on a weight basis, together with air-filled porosity responses, showed large differences between treatments particularly at the time of crop emergency, indicating substantial alterations in the soil profile hydrology. Expressed on a volume basis the increased moisture content near the surface under zero-tillage became more pronounced and the other effects disappeared. Cone resistance responses were proportionately larger than those for bulk density and showed one major difference in that below the depth of ploughing cone resistance was greater for zero-tillage than normal ploughing in the sixth and seventh seasons, but not previously. For bulk density, but probably not for cone resistance, there were no increases after the third season of zero-tillage, the soil reaching an equilibrium density for the current management practices and machinery usage.

Zur Veränderung wichtiger Phosphorbindungsformen in einem Sandlehm-Fleckenstaugley in Abhängigkeit von Düngung und Bearbeitung: On Changes of Important Phosphorus-Binding Forms in a sandy-loamy Sandlehm-Fleckenstaugley in Depence of Fertilization and Cultivation

In a field experiment with modified fertilization and soil tilling on a sandy-loamy Sandlehm-Fleckenstaugley the resulting differences between important forms of phosphorus-binding were investigated after an experimental period of four years, in some cases after three years already. The content of total phosphorus, inorganic and organic-bound phosphorus, aluminium, iron, and calcium phosphates were examined. With increasing phosphorus additions the content of total phosphorus increases as well, immaterial whether the additions Were made with inorganic or organic material. However, when the fertilization variants, treated with the same quantities of phosphorus in mineral or organic form, were compared with each other, it is evident that the organic material increased the total content somewhat more. The content of organic-bound phosphorus was not changed by any measure of fertilization. By deep-ploughing the content was somewhat decreased, compared with shallow and normal ploughing. The changes in total content are caused by changes in the content of inorganic-bound phosphate. The aluminium phosphate content increases with increasing fertilization by about twice the amount. Additions of the same quantities of phosphorus in mineral or organic form yield the same Al-phosphate content. The iron phosphates are the most important inorganic phosphorus-binding form in this soil. Their contant increases with increasing fertilization, a distinct increase is evident with the highest amount of fertilizer. Fertilization and cultivation measures had only slight influence on the calcium phosphates. With reference to the content of these three phosphates, especially with Al- and Fe-phosphates, there are certain differences between the third and the fourth experimental year as far as the Alphosphates show higher content in the third and the Fe-phosphates in the fourth year. These shiftings take place quantitatively. Since these changes happened also without any fertilization, the rearrangements might have happened above all with the soil phosphates. The content of lactate-soluble phosphates are, in the first place, connected with the content of Al- and Fe-phosphates, but hardly with the Ca-phosphates. In an incubation experiment in accordance with the respiratory basic analysis according to Novák, the increased phosphorus demand of the micro-organisms, when supplied with glucose and nitrogen, was covered with Al-phosphates. These favourable nutritional conditions caused a certain increase of the Ca-phosphates as wall, possibly at the expense of the Al-phosphates. In einem Freilandversuch mit Düngungs- und Bearbeitungsvarianten auf einem Sandlehm-Fleckenstaugley, Bodenart sandiger Lehm, wurde nach vier-, in einigen Fällen auch nach dreijähriger Versuchszeit den eingetretenen Differenzierungen zwischen wichtigen Phosphorbindungs-for men nachgegangen. Es wurden untersucht die Gehalte an Gesamt-Phosphor, anorganisch und organisch gebundenem Phosphor, Aluminium-, Eisen- und Calciumphosphaten. Mit steigender Phosphordüngung steigt auch der Gehalt an Gesamt-P an, und zwar unabhängig davon, ob die Zufuhr in mineralischer oder organischer Form erfolgte. Stellt man jedoch die Düngungsvarianten gegenüber, welche gleiche P-Mengen in mineralischer bzw. organischer Form erhielten, so ergibt sich, daß die Zufuhr in organischer Form den Gesamtgehalt etwas stärker erhöhte. Der Gehalt an organisch gebundenem Phosphor erfuhr durch keine Düngungsmaßnahme eine Veränderung. Tiefe Pflugarbeit verminderte die Gehalte etwas gegenüber flacher und normal tiefer. Die Veränderungen im Gesamtgehalt ergeben sich aus den Veränderungen im Gehalt an anorganisch gebundenem Phosphat. Der Gehalt an Aluminiumphosphat steigt mit zunehmender Düngung etwa auf das Doppelte. Verabreichung gleicher Phosphormengen in mineralischer oder organischer Form ergibt gleiche Gehalte an Al-Phosphat. Die Eisenphosphate sind die bedeutendste anorganische P-Bindungsform in diesem Boden. Ihr Gehalt steigt mit steigender Düngung, eine deutliche Erhöhung ist in der höchsten Düngungsstufe zu verzeichnen. Bei den Calciumphosphaten sind die düngungs- und bearbeitungsbedingten Differenzierungen gering. Im Gehalt an diesen drei Phosphaten, insbesondere an Al- und Fe-Phosphaten, bestehen zwischen dem 3. und 4. Versuchsjahr gewisse Unterschiede insofern, als die Al-Phosphate im 3., die Fe-Phosphate im 4. Versuchsjahr höhere Gehalte ausweisen. Diese Verschiebungen erfolgen etwa quantitativ. Da diese Veränderungen auch bei „ungedüngt“ eintraten, dürften die Umlagerungen überwiegend an den im Boden vorhandenen Phosphaten stattgefunden haben. Die Gehalte an laktatlöslichen Phosphaten stehen in erster Linie mit den Gehalten an Al- und Fe-Phosphaten in Beziehung, kaum hingegen mit den Ca-Phosphaten. In einem Inkubationsversuch in Anlehnung an die respiratorische Grundanalyse nach Novák wurde der erhöhte Phosphorbedarf der Mikroorganismen bei Glukose- und Stickstoffverabreichung aus den Al-Phosphaten gedeckt. Diese günstigen Ernährungsbedingungen führten auch zu einer gewissen Erhöhung der Ca-Phosphate, möglicherweise auf Kosten der Al-Phosphate.

The recording of impact loads during tillage

This paper describes equipment for the study of impacts between stones and agricultural implements during soil working operations. A strain gauged probe is mounted on a standard toolbar and can be drawn through the soil at normal ploughing depths and speeds. The resultant force acting at any instant on the nose of the device is calculated from the strain-gauge readings, which are recorded on an analogue tape recorder and replayed on an ultra-violet (u.v.) recorder or a storage oscilloscope in the laboratory at a reduced speed to enable high frequency transient pulses to be studied. The paper also describes some preliminary trials where the device was driven into objects buried in its path.

Soil and cotton responses to tillage and ameliorant treatments in a brown clay soil. 1. Soil responses and water use

Furrow-irrigated cotton was grown for two seasons on a previously uncultivated dense clay soil to which the following treatments had been applied :--normal ploughing (18 cm), precision ripping (30 cm), deep ploughing (40 cm), deep ripping (60 cm), and deep ploughing and deep ripping combined, with and without applications of gypsum at 10 tons an acre or organic matter at 2 1/2 tons an acre. The deep tillage significantly increased the porosity of the subsoil, but this extra porosity had largely been lost by the end of the second season. Neither the gypsum nor the organic matter addition had a significant effect upon its rate of decline. Despite the effect on porosity the deep tillages had only small and mostly non-significant effects upon water increment at irrigation. The gypsum treatment, but not the organic matter, increased water entry to the subsoil at irrigation, and this W-as apparently a result of improved hydraulic conductivity and aggregate stability, particularly in the surface layers. Considerable leaching of chloride occurred from the 30-60 cm subsoil zone in both gypsum treated and deep-tilled plots, but not in organic matter plots, and an accumulation of chloride occurred in the 0-10 cm layer (the hill) in gypsum treated plots. The increased water intake to the subsoil resulting from gypsum treatment was matched by increased water use in the following period, and hence a reduction in relative water deficit of Leaves during the peak period of water demand. Neither the organic matter nor the deep tillages had appreciable influence on water uptake. Water use during periods of peak demand was about 6 mm a day for gypsum treated plots, and this was probably lower than mould have been obtained with water freely available at all times. On the other treatments it can he inferred that water use was even further reduced by lack of available water.

Soil and cotton responses to tillage and ameliorant treatments in a brown clay soil. 2. Growth, yield and quality of cotton

Furrow irrigated cotton was grown in 1965-66 and 1966-67 on previously uncultivated dense clay soil to which the following treatments were applied before sowing in 1965 ; normal ploughing (18 cm), precision ripping (30 cm), deep ploughing (40 cm), deep ripping (60 cm), and deep ploughing and deep ripping combined, with and without application of gypsum at 10 tons an acre or organic matter at 2 1/2 tons an acre. Each of the three deep tillages increased lint yield by about 12 per cent in the first season, but in the second season the combined deep ripping and deep ploughing alone gave a significant increase of 17 per cent. Precision ripping had no influence on yield. The gypsum treatment gave increases in both seasons (16 per cent in 1966 and 34 per cent in 1967) whereas organic matter had no effect. The higher yields were produced from a greater number of larger bolls, on taller, more vigorous plants with more main stem nodes. These effects on plant growth and yield were interpreted as resulting from the changes in subsoil porosity and water entry at irrigation (reported previously). As with the soil properties, the tillage and ameliorant treatments did not interact significantly on plant growth and yield. Changes in the quality of the lint accompanied the yield increases. Deep tillage and particularly gypsum application produced finer (lower Micronaire values), but longer and more elastic fibres than the control. However, differences between seasons were generally greater than those due to treatments, and the lowering of Micronaire values by gypsum or deep tillage could be regarded as either beneficial or deleterious depending on the seasonal conditions during lint development. By improving soil tilth, gypsum application increased seedling establishment and hence yield potential, and this could be of considerable practical significance in commercial crops grown on soils responsive to gypsum.

The soil structure profile under pastures

It has been found that under reconditioning pastures the soil develops a strongly differentiated structure profile within normal ploughing depth. Aggregation (2 mm) as measured by the wet sieving technique was, for short-term subterranean clover and ryegrass pastures, high at the surface but decreased rapidly with depth. In contrast to this, a more vigorous dispersion test showed that the crumbs of these highly aggregated surface layers broke down to give a greater amount of fine material (<50 µ) than did soil from below the old 3-in. cultivation depth. A demonstration of the practical implications was obtained on ploughing in a 3-year pasture. Chisel, mould board, and disc ploughs were used at three depth settings. Where the structure profile was inverted or mixed, infiltration rate and porosity were better maintained during a winter fallow than when the soil was loosened but not inverted.

Water conduction by severed grass roots

It is suggested that part of the increased permeability of soil recently ploughed out from grass could be due to water conduction through the severed roots. Microtome sectioning of a root of Lolium perenne showed a continuous metaxylem element of about 30μ diameter, with only minor restrictions, forming a natural capillary tube. Further, being at the centre of the stele, the metaxylem should persist for some time after the grass has been killed. Hydraulic diameters calculated from laboratory experiments on the rates of water conduction by severed L. perenne roots were in reasonable agreement with the diameter of the metaxylem measured by direct sectioning.Similar experiments on Phleum pratense were more difficult to interpret due to the complexity of the metaxylem, the number of elements not being constant along the root. The rate of water conduction by roots of Dactylis glomeratus was found to be small compared with the other grasses, for although having the largest number of elements they are the smallest in size of any grass examined.The permeability of a severed Lolium perenne root system, calculated on the basis of the surface density of roots found on 4-year-old plots, indicated that the root system should significantly increase the unsaturated permeability of soil at low suctions. To obtain maximum benefit the ‘capillary tubes’ should be severed immediately under the turf and not at ploughing depth. Accordingly, two plots were laid out on old grassland to compare normal autumn ploughing with shallow rototilling on the subsequent germination and growth of spring wheat. In spite of repeated rototilling, however, it proved impossible to kill the grass in the wet winter conditions and the wheat was smothered. A comparison of the suctions developed at 5 cm. in the two plots showed that the unsaturated permeability of the rototilled plot was higher.Although the laboratory results are encouraging there is as yet no conclusive evidence that the natural water supply and drainage system formed by the severed roots is important under field conditions.