scholarly journals Response of P, K, Mg and NO 3 -N contents of carrots to irrigation, soil compaction, and nitrogen fertilisation

2000 ◽  
Vol 9 (4) ◽  
pp. 319-331 ◽  
Author(s):  
L. PIETOLA ◽  
T. SALO
Keyword(s):  
Soil Moisture ◽  
Sprinkler Irrigation ◽  
Weather Conditions ◽  
Nutrient Status ◽  
Soil Condition ◽  
Organic Soil ◽  
Compacted Clay ◽  
Fresh Matter ◽  
N Content ◽  
Mineral Soils

Soils ploughed in autumn were loosened by different tillage tools, or compacted to a depth of 25-30 cm by a tractor weighing 3 Mg (once or three times) before seed bed preparation for carrot under moist soil condition. Sprinkler irrigation was also applied to mineral soils when the soil moisture in top soil was 50% of plant-available water capacity, and the response of additional N application of 30 kg ha-1 was studied in an organic soil. Higher soil moisture tended to promote nutrient uptake, as the P content of carrot tap roots was increased by irrigation in loam. Compaction of organic soil low in P increased P and K contents and uptake by carrot roots and shoots. In severely compacted clay soil, the nutrient use decreased by increasing soil compactness. NO3-N contents were the highest in early season (25-30 mg kg-1 fresh matter) and decreased with advancing season. In loam, NO3-N content was increased by irrigation or loosening. Increasing the N fertilisation of organic soil from 30 kg ha-1 to 60 kg ha-1 increased the NO3-N content 30%. Soil type and its nutrient status, weather conditions, and growth stage had much more significant influence on the P, K, and Mg contents of carrots than soil treatments.

A strategy for concurrently monitoring the plant water potentials of spatially separated forest ecosystems

1986 ◽  
Vol 16 (2) ◽  
pp. 346-351 ◽  
Author(s):  
W. L Strong ◽  
G. H. La Roi
Keyword(s):  
Soil Moisture ◽  
Black Spruce ◽  
Organic Soil ◽  
Jack Pine ◽  
Lower Amount ◽  
Plant Water ◽  
Evergreen Species ◽  
Water Potentials ◽  
Spruce Stands ◽  
Mineral Soils

A technique for estimating plant water potentials in plant communities was used in six forest stands representing a jack pine (Pinusbanksiana Lamb.) and a black spruce (Piceamariana (Mill.) B.S.P.) successional sequence. A set of 31 plants composed of 16 species were measured at 4-day intervals from early May to late August 1982. The six stands had similar patterns of summer plant water potentials with greatest differentiation among species occurring during periods of maximum water stress. Plant water potentials varied more in jack pine stands on sand than in black spruce stands on organic soil. Shallow-rooted ericaceous and (or) evergreen species (e.g., Vacciniummyrtilloides Michx., Vacciniumvitis-idaea L., and Pyrolaasarifolia Michx.) had the widest range of water potentials during summer, whereas deep-rooted Alnuscrispa (Ait.) Pursh had the narrowest range. Maximum morning (0700) water potentials reached−3.1 MPa. All species had fine roots (<2 mm) within the upper 20 cm of the soil, but some species of the Jack Pine Series had roots to 230 cm depth. Soil moisture was usually more available in the upper 20 cm and below 60 cm in mineral soils; the lower amount of soil moisture at middle depths resulted from depletion by plants and lack of downward percolation of precipitation in 1982.

Biology and Control of Black Nightshade (Solanum nigrum) in Cotton (Gossypium hirsutum)

1991 ◽  
Vol 5 (4) ◽  
pp. 713-722 ◽  
Author(s):  
Paul E. Keeley ◽  
Robert J. Thullen
Keyword(s):  
Soil Moisture ◽  
Sprinkler Irrigation ◽  
Yield Losses ◽  
Accelerated Degradation ◽  
Black Nightshade ◽  
Excellent Control ◽  
Late Application ◽  
And Control ◽  
Field Plots ◽  
Weed Resistance

A 4-yr study (1985, 1987, 1988, 1989) was conducted on the same field plots at Shafter, CA to evaluate the efficacy of prometryn in controlling black nightshade on planting beds of cotton. Two rates (1.7 and 2.2 kg ai ha–1) were applied at two times (mid March before the preplant irrigation and early April at cotton planting) each year. Incorporation of prometryn into moist planting beds with a powered rotary tiller operated at 10 cm deeper resulted in excellent control of black nightshade under low to moderate weed pressure in 1985 and 1987. Control of nightshade with early and late applications of 1.7 kg ha–1of prometryn under high weed pressure in 1988 was only 70% at harvest, and yield losses of cotton averaged 25%. Yields of cotton treated with 2.2 kg ha–1of prometryn in 1988 were not significantly different from weed-free plots. Only the late application of 2.2 kg ha–1of prometryn prevented significant cotton losses under extreme weed pressure in 1989. Cotton yield losses with the other prometryn treatments ranged from 78 to 100%. Losses of cotton in weedy-check plots that received only cultivation ranged from 22% in the absence of rain or irrigation at cotton planting in 1987 to as much as 100% when rain fell in 1988 or plots were irrigated at planting in 1989. Plots hoed one time 4 wk after cotton planting yielded an average of 84% as much seed cotton as weed-free plots. In an attempt to determine why the efficacy of prometryn declined between 1985 and 1989, several experiments were conducted in 1988 to 1990 to discover reasons for this poor control of nightshade. Because efforts failed to provide evidence for the movement of the herbicide with water, the development of weed resistance to prometryn, or accelerated degradation of this herbicide in soil, increasing weed seed populations in soil were believed to have contributed greatly to the declining nightshade control from prometryn. The fact that prometryn applied and incorporated into flat soil provided excellent control of nightshade in 1990 under sprinkler irrigation indicated that both soil moisture and incorporation techniques limited activity of prometryn in planting beds in 1988 and 1989. Incomplete control of nightshade plus good soil moisture at planting contributed to the high weed populations in 1988 and 1989.

scholarly journals Examination of the physical state of the soil under conventional and reduced tillage systems

2013 ◽  
pp. 183-186
Author(s):  
Géza Tuba
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Compaction ◽  
Soil Layer ◽  
Weather Conditions ◽  
Penetration Resistance ◽  
Conventional Tillage ◽  
Reduced Tillage ◽  
Deep Soil ◽  
Tillage Systems

he effect of reduced and conventional tillage systems on soil compaction and moisture content in two years with extreme weather conditions is introduced in this paper. The investigations were carried out in a long-term soil cultivation experiment set on a heavy textured meadow chernozem soil at the Karcag Research Institute. In 2010 the amount of precipitation during the vegetation period of winter wheat was 623.3 mm, 2.2 times higher than the 50-year average, while in 2011 this value was 188.7 mm giving only 65% of the average. The examinations were made after harvest on stubbles on 4 test plots in 5 replications in the case of each tillage system. Soil compaction was characterised by penetration resistance values, while the actual soil moisture contents were determined by gravimetry. The values of penetration resistance and soil moisture content of the cultivated soil layer were better in the case of reduced tillage under extreme precipitation conditions. It could be established that regular application of deep soil loosening is essential due to the formation of the unfavourable compact soil layer under 30 cm. Conventional tillage resulted in enhanced compaction under the depth of ploughing, the penetration resistance can reach the value of 4 MPa under wet, while even 8 MPa under dry soil status.

scholarly journals Spatial variability and its scale dependency of observed and modeled soil moisture under different climate conditions

2012 ◽  
Vol 9 (9) ◽  
pp. 10245-10276 ◽  
Author(s):  
B. Li ◽  
M. Rodell
Keyword(s):  
Soil Moisture ◽  
Spatial Variability ◽  
Warm Season ◽  
Weather Conditions ◽  
Data Sets ◽  
Scale Dependency ◽  
Convex Shape ◽  
Climate Conditions ◽  
Spatial Moments

Abstract. Past studies on soil moisture spatial variability have been mainly conducted in catchment scales where soil moisture is often sampled over a short time period. Because of limited climate and weather conditions, the observed soil moisture often exhibited smaller dynamic ranges which prevented the complete revelation of soil moisture spatial variability as a function of mean soil moisture. In this study, spatial statistics (mean, spatial variability and skewness) of in situ soil moisture measurements (from a continuously monitored network across the US), modeled and satellite retrieved soil moisture obtained in a warm season (198 days) were examined at large extent scales (>100 km) over three different climate regions. The investigation on in situ measurements revealed that their spatial moments strongly depend on climates, with distinct mean, spatial variability and skewness observed in each climate zone. In addition, an upward convex shape, which was revealed in several smaller scale studies, was observed for the relationship between spatial variability of in situ soil moisture and its spatial mean across dry, intermediate, and wet climates. These climate specific features were vaguely or partially observable in modeled and satellite retrieved soil moisture estimates, which is attributed to the fact that these two data sets do not have climate specific and seasonal sensitive mean soil moisture values, in addition to lack of dynamic ranges. From the point measurements to satellite retrievals, soil moisture spatial variability decreased in each climate region. The three data sources all followed the power law in the scale dependency of spatial variability, with coarser resolution data showing stronger scale dependency than finer ones. The main findings from this study are: (1) the statistical distribution of soil moisture depends on spatial mean soil moisture values and thus need to be derived locally within any given area; (2) the boundedness of soil moisture plays a pivoting role in the dependency of soil moisture spatial variability/skewness on its mean (and thus climate conditions); (3) the scale dependency of soil moisture spatial variability changes with climate conditions.

Can climate models capture the high amplitudes circumglobal waves and their surface imprints?  

2021 ◽  
Author(s):  
Fei Luo ◽  
Kai Kornhuber ◽  
Frank Selten ◽  
Dim Coumou
Keyword(s):  
Soil Moisture ◽  
Climate Models ◽  
Phase Locking ◽  
Weather Conditions ◽  
Reanalysis Data ◽  
Circulation Types ◽  
Temperature And Precipitation ◽  
Wave Patterns ◽  
Precipitation Anomalies ◽  
June July

&lt;p&gt;Pronounced circumglobal waves can trigger and maintain persistent summer weather conditions by remaining in their preferred phase-locked positions for several weeks in a row. This phenomenon, especially important for wave numbers 5 and 7, has been observed in recent years, but it is unclear whether climate models can reproduce circulation types and their surface imprints.&lt;/p&gt;&lt;p&gt;Here we assess three climate models (EC-Earth3, CESM1.2, and MIROC5) &amp;#160;for their representation of amplified circumglobal waves and associated surface imprints in summer (June, July and August) over 1979-2016. ERA5 reanalysis data is used as reference to assess the models&amp;#8217; performance. We run a series of modeling experiments to understand the source of biases in the climate models: free interactive atmosphere and soil moisture runs (AISI), atmospheric nudged runs (AFSI), soil moisture prescribed runs (AISF), and both atmosphere and soil moisture nudged experiments (AFSF).&lt;/p&gt;&lt;p&gt;We show that all models reasonably well reproduce the climatological wave spectra. Further, both wave 5 and wave 7 are found to exhibit phase-locking behaviors across all models, resulting in similar wave patterns across the hemisphere as compared to reanalysis. The surface imprints are observed in the models as well, but depending on the model, the results vary in strength. We also found the biases in surface temperature and precipitation anomalies mainly come from the atmospheric circulation in the models as these biases reduced considerably from AISI runs to AFSI and AFSF runs where upper atmosphere levels were nudged. Nudging soil moisture also minimizes some biases in the models but not as obvious as nudging the atmosphere.&amp;#160;&lt;/p&gt;&lt;div&gt; &lt;div&gt; &lt;div&gt;&amp;#160;&lt;/div&gt; &lt;/div&gt; &lt;/div&gt;

SPREAD OF TOADFLAX IN SASKATCHEWAN

1963 ◽  
Vol 43 (2) ◽  
pp. 214-221 ◽  
Author(s):  
R. T. Coupland ◽  
S. Zilke ◽  
G. W. Selleck
Keyword(s):  
Soil Moisture ◽  
Good Control ◽  
Weather Conditions ◽  
Survey Sampling ◽  
Linaria Vulgaris ◽  
Precise Data ◽  
Perennial Weeds ◽  
Farm Survey ◽  
Line Transects

During 1949–57, surveys and resurveys were conducted throughout one-third of the settled area of Saskatchewan for the purpose of ascertaining the abundance of several species of introduced persistent perennial weeds and to evaluate their rates of increase. The methods used included an extensive farm-to-farm survey, sampling quarter-sections along transects in heavily infested areas, and resurveys of the same land at intervals. Detailed studies along line transects in various habitats were used during 1954–61 to obtain more precise data concerning increases and decreases in extent of infestations. These studies indicated that, within the area surveyed, 142,702 acres were infested with toadflax (Linaria vulgaris Mill.) in 4,993 quarter-sections. The increase in abundance of the weed was particularly great from 1949 to 1954, while after that date uncultivated infestations spread much less rapidly and cultivated ones were kept under fairly good control. The data indicate that the weed probably responds to weather conditions in such a way as to be favored relative to grasses by deficiency of soil moisture in the upper levels of the soil.

scholarly journals The Unexploited Potential of Nutrient Analysis in Potato Tissues at the Onset of Tuberization for Tuber Yield Prediction

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 103
Author(s):  
Witold Grzebisz ◽  
Karolina Frąckowiak ◽  
Jarosław Potarzycki ◽  
Jean Diatta ◽  
Witold Szczepaniak
Keyword(s):  
Opposite Effect ◽  
Tuber Yield ◽  
Seasonal Pattern ◽  
Nutrient Status ◽  
Reliable Prediction ◽  
N Content ◽  
Nutrient Analysis ◽  
Potato Tuberization ◽  
N Rates ◽  
Yield Decrease

Nutrient analysis of potato leaves in early growth is not sufficient for a reliable prediction of tuber yield. This hypothesis was verified based on a field experiment conducted during 2006–2008. The experimental factors were: nitrogen (N) rates (60, 120 kg ha−1), fertilizers (Urea, Urea + inhibitor—NBPT ([N-(n-butyl) thiophosphoric triamide]), and sulfur rates (0, 50 kg ha−1). Plant material for nutrient determination (N, P, K, Mg, Ca, Fe, Mn, Zn, Cu), which included leaves, stems, and stolons + roots (R+S), was sampled at BBCH 39/40. The marketable tuber yield (MTY) was in the ranges of 43–75, 44–70, and 24–38 t ha−1, in 2006, 2007, and 2008, respectively. The MTY and contents of N, Zn, and Cu, irrespective of the potato tissue, showed the same seasonal pattern, reaching the lowest values in the dry 2008. The N content in stems was the best tuber yield predictor. A shortage of K in stems and Mg and Cu in R+S, due to the opposite effect of Ca, reduced the N content. An N:Ca ratio in stems greater than 10:1 resulted in yield decrease. A reliable indication of nutrients limiting the tuber yield at the onset of potato tuberization requires data on the nutrient status in both leaves and stems.

Quackgrass (Agropyron repens) Interference on Corn (Zea mays)

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 226-234 ◽  
Author(s):  
Frank L. Young ◽  
Donald L. Wyse ◽  
Robert J. Jones
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Leaf Tissue ◽  
Nutrient Status ◽  
Growing Season ◽  
Field Studies ◽  
Growth And Yield ◽  
Limiting Factors ◽  
Corn Yield ◽  
Agropyron Repens

Field studies were conducted to evaluate the effect of quackgrass [Agropyron repens(L.) Beauv. ♯ AGRRE] density and soil moisture on corn (Zea maysL.) growth and yield. Quackgrass densities ranging from 65 to 390 shoots/m2reduced corn yield 12 to 16%. A quackgrass density of 745 shoots/m2reduced corn yields an average of 37% and significantly reduced corn height, ear length, ear-fill length, kernels/row, rows/ear, and seed weight. In the soil moisture study, quackgrass was shorter than corn throughout the growing season, and analyses of corn leaf tissue indicated that quackgrass did not interfere with the nutrient status of the corn. In 1979, soil moisture was not limiting and corn yields were similar in all treatments regardless of irrigation or the presence of quackgrass. In 1980, soil moisture was limited and irrigation increased the yield of quackgrass-free corn. Irrigation also increased the yield of quackgrass-infested corn to a level similar to irrigated corn. When light and nutrients are not limiting factors, an adequate supply of soil moisture can eliminate the effects of quackgrass interference on the growth, development, and yield of corn.

Development of calibration algorithms for selected water content reflectometry probes for burned and non-burned organic soils of Alaska

2010 ◽  
Vol 19 (7) ◽  
pp. 961 ◽  
Author(s):  
Laura L. Bourgeau-Chavez ◽  
Gordon C. Garwood ◽  
Kevin Riordan ◽  
Benjamin W. Koziol ◽  
James Slawski
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Soil Profile ◽  
Soil Moisture Content ◽  
Mineral Soil ◽  
Organic Soil ◽  
Organic Content ◽  
Organic Soils ◽  
Probe Type

Water content reflectometry is a method used by many commercial manufacturers of affordable sensors to electronically estimate soil moisture content. Field‐deployable and handheld water content reflectometry probes were used in a variety of organic soil‐profile types in Alaska. These probes were calibrated using 65 organic soil samples harvested from these burned and unburned, primarily moss‐dominated sites in the boreal forest. Probe output was compared with gravimetrically measured volumetric moisture content, to produce calibration algorithms for surface‐down‐inserted handheld probes in specific soil‐profile types, as well as field‐deployable horizontally inserted probes in specific organic soil horizons. General organic algorithms for each probe type were also developed. Calibrations are statistically compared to determine their suitability. The resulting calibrations showed good agreement with in situ validation and varied from the default mineral‐soil‐based calibrations by 20% or more. These results are of particular interest to researchers measuring soil moisture content with water content reflectometry probes in soils with high organic content.

scholarly journals Effect of Soil Moisture Content and End-Effector Speed on Pick-up Force and Lump Damage for Seedling Transplanting

2019 ◽  
Vol 1 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Mohamed ◽  
Liu
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Soil Condition ◽  
Penetration Resistance ◽  
Force Balance ◽  
High Moisture Content ◽  
High Moisture ◽  
End Effector ◽  
End Effectors

Efficient transplanting has been identified as one of the essential steps towards achieving an increased yield in the farm. However, many factors are affecting these processes such as soil moisture content and the speed of pickup. This study was carried out to investigate the effect of different soil moisture content and pickup speeds on pickup force, balance, resistance, and lump damage during transplanting of seedlings. The results showed that penetration resistance was inversely proportional to the speed and soil moisture content. The highest penetration resistance (38 N) values were recorded under the lowest speed (0.5 mm/s) at the low moisture content; whereas, the lowest penetration resistance was obtained at highest speed (10 mm/s) under high moisture content. The highest pick-up force resistance values were recorded under the lowest speed (0.5 mm/s) at low moisture content than the lowest pick-up force resistance of 1.4 N at (10 mm/s) under the high moisture content. On the other hand, an increase of pick-up force led to a decrease in the pick-up force resistance. The pick-up damage and the pick-up speed are directly proportional—nevertheless, the former increased with a decreasing soil moisture content. The highest pick-up damage values (82%) were observed under the top-most speed (10 mm/s) at high moisture content. It can be concluded that for successful auto-transplanting of seedling the soil condition, the force applied and speed should be taken into consideration. This work will implement an effective seedling-picking performance and basis for the optimal design of end-effectors.

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