scholarly journals Relationship between Root Dostribution of Upland Crops and their Yield : III. Influence of soil moisture levels on root distribution and root dry matter of upland-cultured paddy rice, crossbred rice of paddy rice and upland rice, and upland rice

1981 ◽  
Vol 50 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Hiroharu BANBA ◽  
Takahiro OHKUBO
Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 708
Author(s):  
Phanthasin Khanthavong ◽  
Shin Yabuta ◽  
Hidetoshi Asai ◽  
Md. Amzad Hossain ◽  
Isao Akagi ◽  
...  

Flooding and drought are major causes of reductions in crop productivity. Root distribution indicates crop adaptation to water stress. Therefore, we aimed to identify crop roots response based on root distribution under various soil conditions. The root distribution of four crops—maize, millet, sorghum, and rice—was evaluated under continuous soil waterlogging (CSW), moderate soil moisture (MSM), and gradual soil drying (GSD) conditions. Roots extended largely to the shallow soil layer in CSW and grew longer to the deeper soil layer in GSD in maize and sorghum. GSD tended to promote the root and shoot biomass across soil moisture status regardless of the crop species. The change of specific root density in rice and millet was small compared with maize and sorghum between different soil moisture statuses. Crop response in shoot and root biomass to various soil moisture status was highest in maize and lowest in rice among the tested crops as per the regression coefficient. Thus, we describe different root distributions associated with crop plasticity, which signify root spread changes, depending on soil water conditions in different crop genotypes as well as root distributions that vary depending on crop adaptation from anaerobic to aerobic conditions.


Author(s):  
Adriano S. Nascente ◽  
Luís F. Stone ◽  
Cleber M. Guimarães

An important point in no-tillage system is the time between cover crop glyphosate desiccation and rice sowing. This study aimed to verify the effect of Brachiaria ruziziensis management time before rice sowing on rice yield and its components. The experiment was conducted under greenhouse conditions and consisted of four types of B. ruziziensis management: with Brachiaria and with herbicide (WBWH), without Brachiaria shoots and with herbicide (NBWH), without Brachiaria shoots and without herbicide (NBNH), and with Brachiaria and without herbicide (WBNH), at four times: 30, 20, 10, and 0 days, preceding the rice sowing. The amount of B. ruziziensis dry matter increased as the management was done closer to the rice sowing date. The WBWH and WBNH managements (this one causes the lowest rice grain yield) must be done 30 days before rice sowing; while NBWH management must be done ten or more days before rice sowing. On the other hand, NBNH management (this one favors the best rice grain yield) can be done until rice sowing day. Despite some reduction in rice yield caused by the B. ruziziensis management, when it was done at the proper time the rice grain yield was similar to the control (without Brachiaria sowing and without herbicide application).


1969 ◽  
Vol 50 (2) ◽  
pp. 92-112
Author(s):  
R. Vázquez ◽  
A. Eschenwald-Hess ◽  
M. J. Martínez-Luciano

A field experiment was conducted at Lajas Substation in order to study the effects of four irrigation and three nitrogen levels under three different seeding rates on dry-matter yields of White Native sorghum. The following irrigation treatments were tried: High moisture, plots irrigated when the average soil-moisture suction in the active root-zone reached 0.7 atm.; medium moisture, irrigated when the average soil-moisture suction reached 2.0 atm.; low moisture, irrigated when the average soil-moisture suction reached 5.0 atm., and nonirrigated plots were used as check. The nitrogen levels tested were 40, 80, and 120 pounds per acre per harvest. The seeding rates used were 10, 20, and 30 pounds per acre.


1988 ◽  
Vol 19 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Lotta Andersson

Soil moisture dynamics in the Velen drainage basin (Sweden) were analyzed in order to assess the degree of and the reasons for spatial variation in basin behaviour. The main tool was a modified version of the soil moisture accounting routine in the conceptual runoff model HBV, optimized against neutron probe field data. Simulated soil moisture dynamics, interception and percolation rates agreed well with measurements and other calculations. Integration of simulated evapotranspiration from sites with different characteristics agreed well with water balance computations for the area. It was shown that unsaturated flow through macropores probably occurred after heavy rainstorms. During spring, evapotranspiration was limited to values below the potential (Penmans equation) even at times when no soil moisture deficit existed. Soil moisture differences between forest and grassland (including a deforested site) were, during summer, mainly attributed to differences in the root distribution with depth. The effect of interception on the total evapotranspiration rates was only significant during periods when transpiration demands were low. Soil moisture differences between forest sites were mainly attributed to topography but variations in soil characteristics and root distribution had to be considered, especially during dry periods.


1969 ◽  
Vol 72 (2) ◽  
pp. 203-215 ◽  
Author(s):  
Maurice Eddowes

SUMMARYCompetition among maize plants in the vegetative stage of growth was postponed by application of nitrogen to the seed bed and by maintaining soil moisture near field capacity. The amount of available nitrogen was a critical factor in determining the effect of the competitive balance between nitrogen and light on maize yield. The supply of either affected the capacity of the crop to utilize the other, but ultimately light became the dominant factor.Soil moisture deficits of up to 1.0 in from field capacity, in the early stages of vegetative growth, did not reduce dry-matter accumulation and uptake of nitrogen, but in the absence of weed competition and post-planting cultivation soil moisture losses in the early stages of crop growth may be small.In 1966, maize responded quicker to surface applied than to deep-placed nitrogen and utilized the surface applied nitrogen for dry-matter accumulation more effectively.Provided that there was initially an adequate supply of nitrogen in the seed bed, there appeared to be no advantage to total yield from application of nitrogen top dressings to maize. In the West Midlands, under conditions of adequate nutrient and soil moisture supply, the optimum plant population for commercial production of forage maize was about 40000 per acre.


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