[Mineral nitrogen accumulation and its spatial distribution in soils in dense planting dwarf rootstock apple orchard on the Weibei dry plateau, Northwest China].
0
Citation
0
Reference
10
Related Paper
Abstract:
With the rapid development of dense apple tree plantings with the dwarf rootstock cultivation method, determining accumulation and distribution characteristics of soil mineral nitrogen in densely planted orchards with dwarf rootstock is important to enable scientific fertilization of apple orchards. We investigated densely planted apple orchards with dwarf rootstocks and different plant ages (6 a, 9 a, and 12 a). We collected soil samples under trees, between trees, between rows, and at the midpoints between the trees and rows, and examined the accumulation and distribution characteristics of nitrate, ammonium, and mineral nitrogen. The cumulative amount of nitrate in the 0-300 cm soil layer increased with plant age. The difference between orchards with different plant ages was significant and showed the trend 6 a<9 a<12 a. The cumulative amount of nitrate increased from 1729 kg·hm-2 to 3771 kg·hm-2 with increasing plant age. The ammonium content was low for orchards of all plant ages and had little effect on the accumulation and spatial distribution of mineral nitrogen. There were two accumulation peaks of nitrate nitrogen in the vertical direction. The depth of soil layer where the second accumulation peak was located decreased from 180 cm to 220 cm with increasing plant age. In the horizontal direction, soil nitrate nitrogen content between rows increased from 27 mg·kg-1 to 138 mg·kg-1 with increasing plant age, representing a more than 400% increase. The difference between orchards with different plant ages was significant. In summary, excessive usage of nitrogen fertilizer and serious leaching of nitrate were problematic in all orchards with different ages. Less nitrogen fertilizer should be applied, and anti-seepage measures should be used at the fertilization location to prevent the leaching of nitrate to deep layers.随着苹果矮砧密植栽培模式的迅速发展,揭示矮砧密植苹果园土壤矿质氮的积累与分布特征对果园科学施肥具有重要意义。本研究以不同树龄(6 a、9 a、12 a)的矮砧密植苹果园为对象,在树下、株间、行间以及树干与行间的中间点位置采集土样,分析土壤硝态氮、铵态氮和矿质氮的积累与分布特征。结果表明:0～300 cm土层土壤硝态氮累积量随果园树龄的增大而增加,不同树龄的果园之间差异显著,表现为6 a＜9 a＜12 a,硝态氮累积量由1729 kg·hm-2增长到3771 kg·hm-2;而各树龄果园的铵态氮含量较低,对矿质氮的积累与空间分布特征基本不构成影响。在垂直方向上,硝态氮存在两个累积峰,第2个累积峰所在的土层深度随果园树龄的增大由180 cm下移到220 cm;在水平方向上,行间位置的硝态氮含量随果园树龄的增大由27 mg·kg-1增长到138 mg·kg-1,涨幅超过400%,各树龄果园之间差异显著。综上,各树龄果园均存在氮肥施用过量和硝态氮淋溶严重的问题,生产中应减少果园的氮肥施用量,同时应在施肥位置布设防渗措施阻止硝态氮向土壤深层淋溶。.Keywords:
Orchard
Cite
Citations (0)
Texture (cosmology)
Soil texture
Cite
Citations (2)
Cite
Citations (1)
Peach replant disorder (PRD) is a serious problem for peach growers throughout the United States. PRD refers to the pattern of reduced growth and yield observed in young peach trees planted on soil previously cropped with peaches. The conventional treatment for PRD, pre-plant soil fumigation with methyl bromide (a broad-spectrum biocide) adequately controls the disorder. This suggests that PRD results from harmful interaction(s) between the soil biotic community and peach roots. However, the specific causal agents of PRD are still unknown. Methyl bromide is a known contributor to ozone depletion, and is only available to U.S. growers through Critical Use Exemptions. Therefore, the task of determining the specific cause of PRD has become increasingly important. The overall objective of this research was to provide new insight into causes and potential management options for PRD. Our specific objectives were: (1) to determine whether prunasin-degrading, cyanide-producing bacteria were present in replant soils and could inhibit young peach tree growth, (2) to study fine root dynamics in treated and untreated replant soils using minirhizotrons, and (3) to compare the ability of traditional and non-traditional replant treatments to improve tree growth on a replant site. One experiment was based on the theory that prunasin (a cyanogenic glycoside found in peach tissues) provides a substrate for cyanide production in
Cite
Citations (1)
Abstract Radial trunk growth of mature almond trees under 4 irrigation treatments was measured with Verner dendrometers for 4 consecutive years. Trunk growth rates and total seasonal growth were affected primarily by soil water and secondarily by crop density conditions. In early spring, when soil water was abundant (near field capacity in entire root zone), the rate of trunk growth was inversely correlated with crop density. Later on, trunk growth was influenced more by soil moisture conditions. Irrigation early in the season increased trunk growth rates even though 30 to 40% available water remained throughout the root zone at time of irrigation. Irrigations after mid-season merely maintained the prevailing trunk growth rates.
Growing season
Standing crop
Cite
Citations (7)
Cite
Citations (5)
Crop Rotation
Nitrogen Cycle
Agroecosystem
Cite
Citations (177)
Subsoil
Topsoil
Growing season
Cite
Citations (31)
A field study was conducted in the experimental field of Agricultural Institute, Stara Zagora. Examined the distribution of irrigation water in the soil profile in irrigation in furrow, maize grain. Experience is based on two soil types- Eutric Vertisol and Gleyic Chromic Luvisol. Humidity profiles before and after irrigation showed trends of distribution and redistribution of irrigation water in furrow irrigation, without irrigation and ridge between them. Due to the lateral filtration in both soil types it can be applied in furrow irrigation. The contours of wetting show that during the irrigation period readily available moisture in the active layer does not fall below wilting point. Soil moisture is accumulated in deep layers, which creates conditions for developing a strong root system of plants. Furrow irrigation for maize in the grain increases the productivity of irrigation water and effective use of precipitation fell during the irrigation season of maize grain.
Surface irrigation
Vertisol
Permanent wilting point
Cite
Citations (1)
Scots pine
Growing season
Cite
Citations (65)