EPIC estimates of soil water, nitrogen and carbon under semiarid temperate conditions

1998 ◽  
Vol 78 (3) ◽  
pp. 551-562 ◽  
Author(s):  
G. Roloff ◽  
R. de jong ◽  
C. A. Campbell ◽  
R. P. Zentner ◽  
V. M. Benson
Keyword(s):  
Soil Water ◽  
Environmental Quality ◽  
Spring Wheat ◽  
Potential Evapotranspiration ◽  
Soil Layer ◽  
Triticum Aestivum L ◽  
Total N ◽  
Organic C ◽  
Support Tool

The Environmental Policy Integrated Climate (EPIC) model is an important support tool for environmental management. Previous tests of the model have determined that it is suitable for long-term yield estimation, but it is less precise in assessing annual yield variability. To determine the reasons for the discrepancies between estimated and measured yields, we tested the ability of EPIC version 5300 to predict soil water and soil nitrogen dynamics, using data from a long-term spring wheat (Triticum aestivum L.) rotation experiment in the semiarid prairie region of Canada. Potential evapotranspiration (PET) estimates varied among methods tested: Priestley-Taylor and Penman-Monteith methods resulted in PET means that were about twice those obtained with the Hargreaves and Baier-Robertson methods. The higher PET means were associated with an excessive estimation of net radiation. We used the Baier-Robertson method to generate the other estimates reported herein. EPIC generally overestimated total soil water, but it still allowed clear differentiation among rotation phases and times of the year, and provided adequate estimates of water during the critical shot-blade stage. Water estimates by soil layer were also generally overpredicted, especially at depths from 0.15 to 0.60 m, but we were able to differentiate among rotation phases and times of the year. Precision of these latter estimates was generally low, accounting at most for 27% of the variability, and varied by soil layer, rotation phase and time of the year. Nitrate-N estimates tended to be lower than measured values, especially at depths below 0.3 m and during vegetative growth phases. However, the estimates also allowed us to distinguish among the rotation phases and times of the year. Total N and organic C were satisfactorily estimated by EPIC. In general, EPIC provided adequate long-term estimates of the environmental quality indicators tested. Key words: Environmental quality, environmental modelling, sustainability, spring wheat, fallow, potential evapotranspiration methods

Simulation of soil organic carbon and nitrogen changes in cereal and pasture systems of southern Australia

Soil Research ◽  
1993 ◽  
Vol 31 (4) ◽  
pp. 481 ◽  
Author(s):  
MR Carter ◽  
WJ Parton ◽  
IC Rowland ◽  
JE Schultz ◽  
GR Steed
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Plant Biomass ◽  
Subterranean Clover ◽  
Farming Systems ◽  
Triticum Aestivum L ◽  
Soil Organic C ◽  
Total N ◽  
Organic C

Maintenance and improvement of soil organic matter levels is an important concern in dryland farming systems of temperate regions. The Century soil organic matter model was used to simulate changes in soil organic C and total N under long-term wheat (Triticum aestivum L.) and pasture rotations at five sites in southern Australia. Average declines in soil organic C and total N of 14 and 10%, respectively, in continuous and wheat-fallow systems over a 10 to 20 year period were closely simulated by the model at each site. Additions of N fertilizer (80 kg N ha-1), which prevented soil organic matter decline in continuous wheat systems, was also well represented by the model. Trends in soil organic matter under long-term legume pasture were not adequately simulated by the model, probably due to the 'annual' nature of subterranean clover (Trifolium subterranean L.) in dry seasons and subsequent changes in the ratio of live to dead plant biomass and shoot to root ratios. Overall, the study emphasizes the importance of adequate total plant C production to prevent a decline in soil organic C.

BURNING CROP RESIDUES: EFFECT ON SELECTED SOIL CHARACTERISTICS AND LONG-TERM WHEAT YIELDS

1979 ◽  
Vol 59 (2) ◽  
pp. 79-86 ◽  
Author(s):  
J. F. DORMAAR ◽  
U. J. PITTMAN ◽  
E. D. SPRATT
Keyword(s):  
Spring Wheat ◽  
Crop Residues ◽  
Soil Characteristics ◽  
Chelating Resin ◽  
Available P ◽  
Total N ◽  
Organic C ◽  
Water Stable Aggregates ◽  
Straw Burning

Soils from a long-term spring wheat — spring wheat — fallow crop rotation study at Lethbridge, Alberta, and two similar crop rotations at Indian Head, Saskatchewan, were analyzed for pH, organic C, total N, chelating resin-extractable C, polysaccharides, water-stable aggregates, NH4-N, NO3-N, and available P. Several agronomic practices, including straw burning, have been tested in the rotations. At Lethbridge, soil samples from the straw-burning treatment showed a decrease (P < 0.05) in soil polysaccharides and in the percentage of water-stable aggregates. At Indian Head, where straw was burned, organic C and polysaccharide content of all soils were decreased (P < 0.05), and NH4-N and available P were decreased (P < 0.05) in some soils. The other soil characteristics examined were not affected by burning of the previous crop residue or, as with available P, reacted differently at different sites. Long-term wheat yields tended to be greater in all experiments when straw was not burned. On the basis of the results obtained, burning of crop residues on a long-term basis must be discouraged.

SOIL ORGANIC MATTER CHARACTERISTICS AFTER LONG-TERM CROPPING TO VARIOUS SPRING WHEAT ROTATIONS

1987 ◽  
Vol 67 (4) ◽  
pp. 845-856 ◽  
Author(s):  
H. H. JANZEN
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Fertility ◽  
Crop Rotation ◽  
Spring Wheat ◽  
N Mineralization ◽  
Soil Layer ◽  
Organic C ◽  
C And N

Soil from a long-term crop rotation study conducted at Lethbridge, Alberta was analyzed to determine the influence of various spring wheat rotations with and without perennial forages on total and mineralizable soil organic matter contents. Crop rotations considered included: continuous wheat (W), fallow-wheat (FW), fallow-wheat-wheat (FWW), and fallow-wheat-wheat-forage-forage-forage (FWWAAA) in which the forage was a mixture of alfalfa and crested wheat grass. The organic C and N contents of soil after 33 yr of cropping were highest in treatments W and FWWAAA, and decreased with increasing frequency of fallow in the rotation. The inclusion of the perennial forage in the rotation did not increase organic C and N levels above those observed in the continuous wheat treatment (W). Differences in levels of mineralizable organic matter among treatments, as measured in laboratory incubations, were much greater than differences in total organic matter content among treatments. In the surface soil layer (0–15 cm), N mineralization was significantly higher in treatment W than in treatments FWW and FWWAAA, and was more than twice that observed in treatment FW. In the subsurface soil layer (15–30 cm), N mineralization was greatest in treatment FWWAAA when sampled just after the plowdown of forage. Effects of crop rotation on C mineralization were similar to those observed for N. Levels of mineralized organic matter were closely related to levels of "light fraction" material (specific gravity < 1.59 g cm−3), which is believed to consist primarily of incompletely decomposed organic matter of plant origin. Differences in amounts of mineralizable organic matter among treatments were attributed to varying frequencies and patterns of crop residue additions. The pronounced effects of crop rotation on the distribution of organic matter among labile and humified organic matter will have a strong impact on soil fertility and may need to be taken into consideration in the development of fertilizer recommendations. It was concluded that inclusion of perennial forages in spring wheat rotations for the purpose of enhancing soil fertility and organic matter levels was not justified under semiarid conditions. Key words: Carbon, nitrogen, mineralization

scholarly journals Distribution and vertical stratification of carbon and nitrogen in soil under different managements in the pampean region of Argentina

2011 ◽  
Vol 35 (6) ◽  
pp. 1985-1994 ◽  
Author(s):  
Carina Rosa Álvarez ◽  
Alejandro Oscar Costantini ◽  
Alfredo Bono ◽  
Miguel Ángel Taboada ◽  
Flavio Hernán Gutiérrez Boem ◽  
...  
Keyword(s):  
Soil Layer ◽  
Conventional Tillage ◽  
No Tillage ◽  
Tillage Systems ◽  
Total N ◽  
Organic C ◽  
C Storage ◽  
C Pools ◽  
No Till ◽  
Total Organic C

One of the expected benefits of no-tillage systems is a higher rate of soil C sequestration. However, higher C retention in soil is not always apparent when no-tillage is applied, due e.g., to substantial differences in soil type and initial C content. The main purpose of this study was to evaluate the potential of no-tillage management to increase the stock of total organic C in soils of the Pampas region in Argentina. Forty crop fields under no-tillage and conventional tillage systems and seven undisturbed soils were sampled. Total organic C, total N, their fractions and stratification ratios and the C storage capacity of the soils under different managements were assessed in samples to a depth of 30 cm, in three layers (0-5, 5-15 and 15-30 cm). The differences between the C pools of the undisturbed and cultivated soils were significant (p < 0.05) and most pronounced in the top (0-5 cm) soil layer, with more active C near the soil surface (undisturbed > no-tillage > conventional tillage). Based on the stratification ratio of the labile C pool (0-5/5-15 cm), the untilled were separated from conventionally tilled areas. Much of the variation in potentially mineralizable C was explained by this active C fraction (R² = 0.61) and by total organic C (R² = 0.67). No-till soils did not accumulate more organic C than conventionally tilled soils in the 0-30 cm layer, but there was substantial stratification of total and active C pools at no till sites. If the C stratification ratio is really an indicator of soil quality, then the C storage potential of no-tillage would be greater than in conventional tillage, at least in the surface layers. Particulate organic C and potentially mineralizable C may be useful to evaluate variations in topsoil organic matter.

scholarly journals Soil water cycle and crop water use efficiency after long-term nitrogen fertilization in Loess Plateau

2012 ◽  
Vol 59 (No. 1) ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
W. Liu ◽  
Q. Xue ◽  
T. Dang ◽  
C. Gao ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Cycle ◽  
Triticum Aestivum L ◽  
Growing Seasons ◽  
Water Recharge ◽  
Use Efficiency ◽  
N Management

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20&ndash;60 cm, increased water recharge by 16&ndash;21 mm, and decreased ASWS by 89&ndash;133 mm in 0&ndash;300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246&ndash;1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was &lt; 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.

Economics of fertilizer-N management for zero-tillage continuous spring wheat in the Brown soil zone

1992 ◽  
Vol 72 (4) ◽  
pp. 981-995 ◽  
Author(s):  
R. P. Zentner ◽  
F. Selles ◽  
C. A. Campbell ◽  
K. Handford ◽  
B. G. McConkey
Keyword(s):  
Risk Aversion ◽  
Soil Water ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Zero Tillage ◽  
Fertilizer N ◽  
Soil Zone ◽  
Medium Risk ◽  
N Management ◽  
Wheat Price

Optimum use of fertilizer inputs requires consideration of factors that influence plant response and those that govern the decisions of producers. The response of spring wheat (Triticum aestivum L.) to soil water and fertilizer N (FN) was assessed in a 9-yr zero-tillage study conducted on a medium-texture, Orthic Brown Chernozem at Swift Current, Saskatchewan. These data were used to assess the economic merit and risk considerations of alternative fertilizer-N management systems when combined with snow-trapping to enhance soil-water reserves. The fertilizer-N systems included rates from 0 to 100 kg ha−1; spring versus fall applications, and deep banding versus surface broadcasting. Tall trap strips of cereal stubble (40–60 cm tall by 90–120 cm wide, spaced every 6 m and running perpendicular to prevailing winds) were used for snow trapping and compared with stubble cut at a uniform standard height of 15–20 cm. The results showed that optimum fertilizer-N rates (FN) varied directly with soil-water (SW) reserves (available water in 0–120-cm depth measured in spring) and the probability distribution for 1 May to 31 July precipitation, and inversely with soil N (SN) (NO3 N in 0–60-cm depth measured in the previous fall), ratio of fertilizer-N cost to wheat price, and the level of risk aversion held by producers. The optimum FNs were highest for spring and fall banding; they were 3–14 kg ha−1 lower for spring broadcasting and 7–22 kg ha−1 lower with fall broadcasting. The optimum rates increased 3.7–5.7 kg N ha−1 for each 10-mm increase in SW, with the higher rates associated with high SN. The FNs declined 5 kg ha−1 for each additional year that the land was cropped continuously. For producers seeking to maximize expected profit or those with low risk aversion, the optimum FNs were considerably higher than those recommended by the Saskatchewan Soil Testing Laboratory (SSTL). In contrast, the FNs for producers with high risk aversion were generally lower than those of SSTL. The SSTL-recommended rates were most appropriate for producers with medium risk aversion. The study found no single combination of timing and method of fertilizer-N placement to be superior in all cases. Spring and fall banding generally provided higher net margins than broadcasting fertilizer N when SW and wheat prices were high, whereas spring broadcasting was best when SW and wheat prices were lower. The economic benefit from snow trapping averaged $9–$32 ha−1 depending on FN and wheat price; however, there was little benefit or a small loss in some years when infiltration of meltwater was low or winter snowfall was minimal.Key words: Yield, fertilizer N, soil water, optimum rates, riskiness, profit

scholarly journals Short- and Long-Term Effects of Lime and Gypsum Applications on Acid Soils in a Water-Limited Environment: 1. Grain Yield Response and Nutrient Concentration

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1213 ◽  
Author(s):  
Geoffrey C. Anderson ◽  
Shahab Pathan ◽  
James Easton ◽  
David J. M. Hall ◽  
Rajesh Sharma
Keyword(s):  
Grain Yield ◽  
Soil Layer ◽  
Acid Soils ◽  
Triticum Aestivum L ◽  
Nutrient Concentrations ◽  
Yield Response ◽  
Long Term Effects ◽  
Grain Yields ◽  
Growing Seasons

Surface (0–10 cm) and subsoil (soil layers below 10 cm) acidity and resulting aluminum (Al) toxicity reduce crop grain yields. In South Western Australia (SWA), these constraints affect 14.2 million hectares or 53% of the agricultural area. Both lime (L, CaCO3) and gypsum (G, CaSO4) application can decrease the toxic effect of Al, leading to an increase in crop grain yields. Within the region, it is unclear if G alone or the combined use of L and G has a role in alleviating soil acidity in SWA, due to low sulfate S (SO4–S) sorption properties of the soil. We present results from three experiments located in the eastern wheatbelt of SWA, which examined the short-term (ST, 2 growing seasons), medium-term (MT, 3 growing seasons), and long-term (LT, 7 growing seasons over 10 years) effects of L and G on grain yield and plant nutrient concentrations. Despite the rapid leaching of SO4–S and no self-liming impact, it was profitable to apply G, due to the significant ST grain yield responses. The grain yield response to G developed even following relatively dry years, but declined over time due to SO4–S leaching. At the LT experimental site had received no previous L application, whereas, at the ST and MT sites, L had been applied by the grower over the previous 5–10 years. For the LT site, the most profitable treatment for wheat (Triticum aestivum L.) grain yield, was the combined application of 4 t L ha−1 with 2 t G ha−1. At this site, the 0–10 cm soil pHCaCl2 was 4.6, and AlCaCl2 was greater than 2.5 mg kg−1 in the 10–30 cm soil layer. In contrast, at the ST and MT sites, the pHCaCl2 of 0–10 cm soil layer was ≥5.5; it was only profitable to apply G to the MT site where the soil compaction constraint had been removed by deep ripping. The use of L increases soil pHCaCl2, resulting in the improved availability of anions, phosphorus (P) in the LT and molybdenum (Mo) at all sampling times, but reduced availability of cations zinc (Zn) in the LT and manganese (Mn) at all sampling. The application of G reduced Mo concentrations, due to the high SO4–S content of the soil.

EFFECTS OF DIFFERENT SEEDING MACHINES ON SPRING WHEAT PRODUCTION UNDER VARIOUS CONDITIONS OF STUBBLE RESIDUE AND SOIL COMPACTION IN NO-TILL ROTATIONS

1977 ◽  
Vol 57 (2) ◽  
pp. 81-91 ◽  
Author(s):  
C. W. LINDWALL ◽  
D. T. ANDERSON
Keyword(s):  
Spring Wheat ◽  
Soil Compaction ◽  
Soil Layer ◽  
Triticum Aestivum L ◽  
Soil Bulk Density ◽  
Wild Oats ◽  
No Till ◽  
Seed Placement ◽  
Loam Soil ◽  
Chemical Fallow

The effectiveness of several commercial seeders and an experimental triple-disc press drill was assessed on a silt loam soil at Lethbridge over a 7-yr period on fields receiving chemical weed control instead of tillage between crops. The double- and triple-disc press drills generally failed to penetrate untilled surfaces adequately when soil bulk density in the upper 5 cm exceeded about 1.2 g/cm3 or when the quantity of surface residue exceeded about 3,700 kg/ha. Hoe openers penetrated the soil but failed to clear heavy residues when stubble and straw lengths were excessive (> 25 cm). In 2 of the 7 yr, yields of spring wheat (Triticum aestivum L.) on small plots seeded with the double- and triple-disc drills were superior to those seeded with the wide-spaced hoe drill (1,159 vs. 721 kg/ha in 1969, and 667 vs. 573 kg/ha in 1973). Yield differences were primarily due to wild oats (Avena fatua L.), which germinated because of the tillage action of hoe openers, in ridge areas between rows and which, despite the use of herbicides, seriously reduced yields from wide-spaced rows (23 and 36 cm). In the other years, yields were similar for all seeding methods. On 0.4-ha chemical fallow fields, yields were up to 51% lower within sprayer wheel traffic areas (bulk densities of 1.2 g/cm3 or greater in the 0- to 5-cm soil layer) because of shallow seed placement when double-disc drills were used but not when hoe drills were used.

EFFECTS OF MOISTURE STRESS AT EARLY HEADING AND OF NITROGEN FERTILIZER ON THREE SPRING WHEAT CULTIVARS

1973 ◽  
Vol 53 (1) ◽  
pp. 1-5 ◽  
Author(s):  
S. DUBETZ ◽  
J. B. BOLE
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Spring Wheat ◽  
High Stress ◽  
Moisture Stress ◽  
Triticum Aestivum L ◽  
Kernel Weight ◽  
Soil Water Stress ◽  
Boot Stage ◽  
Four Levels

Three cultivars of spring wheat (Triticum aestivum L.) were grown at four levels of N fertilizer in metal lysimeters protected from rain by an automatic rain shelter. A soil water stress of 8 bars was developed in one-half of the lysimeters at the early boot stage. Water stress reduced yield by severely decreasing the number of kernels per spike. Tillering was not affected and kernel weight was increased. Pitic 62 withstood the high stress better than Manitou or Kenhi. N enhanced yield by increasing tillering. Kernel weight was unaffected by N, and the number of kernels per spike was decreased. Pitic, which had a higher number of kernels per spike, outyielded Manitou and Kenhi. The protein content of Manitou was higher than that of the other two cultivars. The cultivars differed in their reaction to soil water stress and N.

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