Corn Root Effects on the Nitrogen-Supplying Capacity of a Conditioned Soil (original) (raw)
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Plant and Soil, 2010
To understand how pulse and oilseed crops might use nitrogen (N) more efficiently under varying levels of water and N availability in soil, we conducted a 2-year field study to monitor N accumulation in aboveground (AG-N) and root material at five growth stages, for canola (Brassica napus L.), mustard (Brassica juncea L.), chickpea (Cicer arietinum L.), dry pea (Pisum sativum L.) and lentil (Lens culinaris Medicum) alongside spring wheat (Triticum aestivum L.). Crops were grown in lysimeters (15 cm diameter × 100 cm deep) installed in the field in southern Saskatchewan, Canada. AG-N in all crops was greater under high-water than under low-water conditions. In oilseeds and wheat, AG-N increased until flowering then tended to level off, while in pulses it increased gradually to maturity. At maturity, dry pea and wheat had the greatest AG-N and mustard the least. Enhanced water availability increased seed N but did not affect straw N; consequently, N harvest index was greater under high-water than under lowwater conditions. Root N increased until late-flowering or late-pod (dough stage in wheat) then decreased to maturity. Mustard had the lowest root N, chickpea the second lowest, and canola, wheat, dry pea, and lentil the highest. Improved water availability increased root N for oilseeds and wheat but did not affect root N in pulses. At maturity, average root N of oilseeds, pulses, and wheat was 14, 17, and 20 kg ha-1 , respectively. At the seedling stage pulse crops had about 27% of total plant N in their roots, a much greater proportion than for the non-legumes. However, by maturity all crops had about 14% of plant N in their roots. Soil NO 3-N increased gradually between seedling and maturity in non-legumes but in pulses there was a sharp spike at early flowering. Estimated apparent net N mineralized was similar for wheat and pulse crops which were greater than for canola and mustard. Soil N amounts and temporal change patterns varied substantially among crops evaluated, and these differences need to be considered in the development of diverse cropping
Corn Response to Nitrogen Fertilization in a Soil with High Residual Nitrogen
Agronomy Journal, 2005
County, a major fruit-and vegetable-producing area. High N fertilizer rates (100 to 300 kg N ha Ϫ1 ) are applied High levels of residual NO 3 -N are present in the soils of the Arkanby onion growers to optimize yields without regard for sas River Valley in Colorado where alfalfa (Medicago sativa L.), grains, fruits, and vegetable crops are produced. This study evaluated soil test NO 3 -N levels (Bartolo et al., 1995(Bartolo et al., , 1997. the use of continuous corn (Zea mays L.) to reduce residual N levels Soil test results from the Colorado Arkansas Valley in a furrow-irrigated, silty clay soil. Fertilizer N needed to maintain area and Otero County indicate high levels of residual optimum corn yields following watermelon [Citrullus lanatus (Thunb.) soil NO 3 -N (Dr. Lorenz Sutherland, USDA-NRCS, La-Matsum. and Nakai], and its impacts on NO 3 -N leaching potential Junta, CO, personal communication, 1998). Producers were also evaluated. Treatments evaluated from 2000 through 2003 in the area often think that the soils are just inherently included two N sources (urea and Polyon) and six fertilizer N rates. high in available N and do not associate the high level Corn grain yields were not significantly increased by N fertilization of residual soil N with past and current N management the first year following watermelon but increased with increasing practices. Halvorson et al. (2002) found 355 kg NO 3 -N residual soil NO 3 -N levels the second year without additional N fertilha Ϫ1 in the 0-to 60-cm soil profile and 785 kg NO 3 -N ization and increased by N fertilization in the third and fourth years. Nitrogen source did not significantly affect corn grain yields, residual ha Ϫ1 in the 0-to 180-cm soil depth before planting onion soil NO 3 -N, or N fertilizer use efficiency (NFUE). Nitrogen use effi-
Root and inorganic nitrogen distributions in sesbania fallow, natural fallow and maize fields
Plant and Soil, 1997
One hypothesis for a benefit of integrating trees with crops is that trees with deep root systems can capture and "pump up" nutrients from below the rooting zone of annual crops. Few studies have compared both root and nutrient distribution for planted trees, crops and grassland vegetation. A field study was conducted on a Kandiudalfic Eutrudox in the highlands of western Kenya to measure rooting characteristics and distribution of inorganic N and water in three land-use systems (LUS): (i) Sesbania sesban (L.) Merr. fallow, (ii) uncultivated natural weed fallow and (iii) unfertilized maize (Zea mays L.) monoculture. The maximum rooting depth was 1.2 m in the maize LUS, 2.25 m in a 13-month-old natural fallow, and > 4 m in a 15-month-old sesbania fallow. Total root length was 1.26 km m 2 for the maize LUS, 5.98 km m 2 for the natural fallow, and 4.56 km m 2 to 4 m for the sesbania fallow. Root length to 1.2 m was greater (p < 0.01) for natural fallow than for maize and sesbania fallow. A considerable portion of the sesbania root length to 4 m was in the subsoil; 47% was at 1.2 to 4 m and 31% was at 2.25 to 4 m. Deep rooting of sesbania coincided with lower soil water below 2 m in the sesbania fallow than the natural fallow. Nitrate-N, but not ammonium-N, to 4 m was affected by LUS. Total nitrate to 4 m was 199 kg N ha 1 for the maize LUS, 42 kg N ha 1 for the natural fallow and 51 kg N ha 1 for the sesbania fallow. Soil nitrate in the maize LUS was highest at 0.3 to 1.5-m depth on this Oxisol with anion sorption capacity. No such accumulation of subsoil nitrate was present under sesbania and natural fallow.
Nitrogen Storage with Cover Crops and Nitrogen Fertilization in Tilled and Nontilled Soils
Agronomy Journal, 2008
A gronomy J our n al • Volume 10 0 , I s sue 3 • 2 0 0 8 619 ABSTRACT Improved crop and N management practices are needed to increase soil N storage so that N fertilization rate and the potential for N leaching can be reduced in tilled and nontilled soils. We examined the infl uence of cover crops and N fertilization rates on N inputs from cover crops, cotton Gossypium hirsutum L.) and sorghum [Sorghum bicolor (L.) Moench] and soil total N (STN) content at the 0-to 120-cm depth in no-tilled, strip-tilled, and chisel-tilled Dothan sandy loam (fi ne-loamy, kaolinitic, thermic, Plinthic Kandiudults) from 2000 to 2002 in central Georgia. Cover crops were legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch + rye)
Effects of nitrogen fertilizer on the composition of two prairie plant communities
Community Ecology, 2005
The objective of this study was to determine the effect of nitrogen (N) application on the carbon (C) and N composition of maize roots and their decomposition dynamics at the depths of 15 cm and 45 cm. Maize roots were collected from 0, 120, and 240 kg N ha À1 fertilized plots (R 0 , R 120 , and R 240 , respectively) of a 7-year long-term field experiment. Maize roots were mixed (2% w/w) with soil samples taken from depths of 15 and 45 cm. The mixtures were added to litter bags and buried at 15 and 45 cm depths in the field for 386 days. The root N content was 90e104% greater, the C to N ratio was 43e50% less, and the lignin to N ratio was 51e57% less in the roots of N fertilized (R 120 and R 240) compared with no N fertilized (R 0). Compared to the R 0 addition soil samples, the contents of mineral N, microbial biomass C, and soluble organic C in soils mixed with R 120 and R 240 were greater by 23e37%, 143e297%, and 20e118%, respectively. After 386 days, the remaining C content in roots ranged from 25 to 31% in the R 120 and R 240 samples compared to 36e38% in R 0 samples. Therefore, the increased N content and decreased C to N ratio with fertilization resulted in slightly faster root decomposition. Nevertheless, maize roots from N fertilized plots left more organic C in the soil due to their much greater biomass; therefore, N fertilization led to a greater C input. We conclude that N fertilization affects not only the composition of maize roots, but also their decomposition in soil.
Agronomy Journal, 2007
Management practices may influence soil N levels due to crop uptake and leaching. We evaluated the effects of three tillage practices [no-till (NT), strip till (ST), and chisel till (CT)], four cover crops [hairy vetch (Vicia villosa Roth), rye (Secale cereale L.), vetch 1 rye biculture, and winter weeds or no cover crop], and three N fertilization rates (0, 60-65, and 120-130 kg N ha 21 ) on NH 4 -N and NO 3 -N contents in Dothan sandy loam (fine-loamy, kaolinitic, thermic, Plinthic Paleudults), and N uptake by cotton (Gossypium hirsutum L.) and sorghum [Sorghum bicolor (L.) Moench] from 2000 to 2002 in central Georgia. Nitrogen content was higher in vetch and vetch 1 rye than in rye and weeds. Soil NH 4 -N content at 0 to 30 cm was higher at harvest than at planting, and higher in NT or vetch with 120 to 130 kg N ha 21 than with other treatments. The NO 3 -N content at 0 to 120 cm varied with date of sampling and was higher with vetch than with rye and weeds. The NO 3 -N content at 0 to 10 cm was higher in CT with vetch than in NT and ST with rye or weeds. , N loss from crop residue and soil at 0 to 120 cm was higher with vetch than with other cover crops. Nitrogen removed by cotton lint was higher with rye than with other cover crops in 2000 and higher with 0 and 60 than with 120 kg N ha 21 in 2002, but N removed by sorghum grain and cotton and sorghum biomass were higher with vetch than with rye, and higher with 120 to 130 than with 0 kg N ha 21 . Because of higher N supply, vetch increased soil mineral N and cotton and sorghum N uptake compared with rye, but also increased the potential for N leaching. The potential for N leaching can be reduced and crop N uptake can be optimized by mixing vetch with rye.
2018
The article presents the results of 3-year field tests aimed at evaluating the effect of the nitrogen dose balance based on the Nmin content. Nmin was evaluated in the context of the distribution in the soil profile and the effect of the type of nitrogen fertilizer on production efficiency indicators and the use of nitrogen in maize grain. In order to verify the assumptions, we determined the amount of nitrogen collected with grain yield, Nmin percentage in total nitrogen uptake with grain yield, agricultural and physiological efficiency and utilization of nitrogen and nitrogen Nmin content in the autumn after maize harvest. It has been shown that developing maize accumulates mineral nitrogen (Nmin) present in the soil in the rooting zone, especially during dry years. Incorporating nitrogen dose in the algorithm of the soil component pool significantly improves the performance indicators of the component application. It is possible for a fertilizer to exceed 100% of nitrogen utiliza...
Effect of nitrogen application on the A N value of soil
Biology and Fertility of Soils, 1993
Pot experiments were conducted with two soils, from Rottenhaus and Seibersdorf in Austria, to ascertain whether the rate of fertilizer N application and the test crop would influence the amount of N available in the soil as assessed by the A-value method. 15N-labelled fertilizer was applied at rates of 10, 25, 40, 60, and 100 mg N kg-t soil, corresponding approximately to 20, 50, 80, 120 and 200 kg N hat respectively, and two crop species, barley (Hordeum vuIgare L.) and non-nodulating soybean (Glycine max L.) were used to determine the soil AN value under the various fertilizer regimes. The results showed that the Rottenhaus soil had a higher A N value than the Seibersdorf soil, suggesting that the former was more fertile than the latter. The A N values of both soils were significantly affected by the level of N application. When grown in the same soil, the two test crops showed significantly different fertilizer use efficiency and per cent N derived from fertilizer when the rate of N application exceeded 20 kg ha-1. Thus, the AN value as determined by the two test crops differed significantly for the same soil when the rate of N application was greater than 20 kg/ha. The difference was greater when the soil fertility level was high. The dependence of the A M value on the level of N application and the species of crop seriously compromises the suitability of this method for determining plant-associated N2 fixation. Hence, considerable caution is required when using this method to estimate plant-associated N 2 fixation.