=Paper=
{{Paper
|id=Vol-1152/paper59
|storemode=property
|title=On the Go Measurements of Penetration Resistance and Yield and the Effect of Deep Loosening
|pdfUrl=https://ceur-ws.org/Vol-1152/paper59.pdf
|volume=Vol-1152
|dblpUrl=https://dblp.org/rec/conf/haicta/Bolenius11
}}
==On the Go Measurements of Penetration Resistance and Yield and the Effect of Deep Loosening==
https://ceur-ws.org/Vol-1152/paper59.pdf
On the go measurements of penetration resistance and
yield and the effect of deep loosening
Elisabeth Bölenius1
1
Swedish University of Agricultural sciences, Department of Soil and Environment
P.O. Box 7014, 75007 Uppsala, Sweden, e-mail: Elisabeth.Bolenius@slu.se
Abstract. A horizontal, on-line penetrometer has been used on several fields in
Sweden to measure penetration resistance. The yield on these fields have been mapped
and compared to the penetration resistance. In some of the fields, deep loosening has
been done on parts of the field in order to be able to study the effects on the yield.
Some correlation of higher penetration resistance and lower yield has been found but
no positive effect of the deep loosening was discovered.
Keywords: GIS, site-specific measurements, penetration resistance, yield
1 Introduction
Yield variations within fields can be very high, several tons of grain per hectare
(Thylén, 1997). If the reasons for these variations are known, site-specific inputs can
save resources, the negative effects on the environment can be reduced and yield
levels can be maintained or even increased (Robert, 1999). Relationships between
soil physical parameters and yield, especially in the subsoil, are seldom studied, often
due to labour intensive, and therefor expensive, methods of measuring such
parameters. The spatial variation in cone index and other physical parameters has
been studied by a number of researchers but few have studied the relationship with
yield (Isaac et al, 2002; To & Kay, 2005). A large Swedish study on yield variations
in sugar beet showed that factors influencing root development and water transport in
soil had the largest effect on yield (Berglund et al, 2002).
The objective of the present study was to use a site-specific horizontal, on-line, soil
penetrometer for studying soil penetration resistance and its correlation with yield.
The effects of deep loosening on yield was also studied.
2 Equipment
A four-share parallel-plough was modified to support three parallel, horizontally
mounted, soil penetrating cones, (see figure 1 and 2). The cone-angle was 30°, with a
base diameter of 6.3 cm. The cone was connected to a Bosch draught sensor capable
of registering forces between –25 kN and +25 kN. The instrument is capable of
measuring soil penetration resistance at three depths (10, 30 and 50 cm), speed and
position which are recorded with a Trimble SweeEight GPS every second. The
________________________________
Copyright ©by the paper’s authors. Copying permitted only for private and academic purposes.
In: M. Salampasis, A. Matopoulos (eds.): Proceedings of the International Conference on Information
and Communication Technologies
for Sustainable Agri-production and Environment (HAICTA 2011), Skiathos, 8-11 September, 2011.
693
instrument was used at a speed of approximately 1.5 m s -1 and was equipped with a
stone release mechanism and a system to record actual working depth every second.
The 1000 Hz signal from the draught sensor was reduced to a 1 Hz signal to lessen
the noise.
Fig 1. Soil penetrating cone Fig 2. One of the three
and draught sensor. soil penetrating cones.
3 Results
Fig. 3 shows a yield map for a field while Fig. 4 shows data from penetration
resistance measurements at 30 cm depth performed after harvest. There was an
inverse correlation between penetration resistance and yield (Figs. 3 and 4) with
higher yields obtained at areas of lower resistance. The left part of the maps show
both a higher yield (fig. 3) and lower penetration resistance (fig 4) and the opposite is
true for the right part of the map.
Fig. 3. Yield of spring barley (ton ha-1).
694
Fig. 4. Penetration resistance (kPa) at 30 cm depth.
Figure 5 shows a field where parts of the field was deep loosened. Some
differences could be seen in penetration resistance between loosened and unloosened
parts of the field (fig 6) but these differences was however not visible on the yield
map.
Fig. 5. The strips show the area that was Fig. 6. Penetration resistance at 30 cm.
deep loosened. The red and green dots show Measurements done in September.
places that were more intensely sampled.
695
3 Conclusions
The horizontal penetrometer worked well in the field. The signals were stable and the
construction was sufficiently robust to tolerate stones in the soil. The measurements
show that variations in penetration resistance can explain part of the variation in crop
yield. This horizontal, on-line penetrometer can measure a large area considerably
faster than a traditional penetrometer, which will make it easier to incorporate soil
physical parameters into precision agriculture.
References
1. Isaac, N.E., Taylor, R.K., Staggenborg, S.A., Schrock, M.D. and Leikam, D.F.,
(2002) Using cone index data to explain yield variation within field. Agricultural
engineering. 4, 19-33.
2. Robert, P. (1999) Precision Agriculture: research needs and status in the
USA. In: Precision Agriculture ´99, J.V. Stafford (Ed), UK, BIOS
Scientific Publishers, pp. 19-33.
3. Thylén, L., (1997). Consistency in yield variation and optimal nitrogen rate. In:
Stafford J.V. (Ed), Precision Agriculture ´97, UK, BIOS Scientific Publishers, pp.
345-350
4. To, J. and Kay B.D., (2005). Variation in penetrometer resistance with soil
properties: The contribution of effective stress and implications for pedotransfer
functions. Geoderma 126, 261-276
696