Stress Day Index Research Articles

Maize response to temporary floods under ambient on-farm conditions of the West African Sahel

With the ongoing global warming, the occurrence and amplitude of extreme weather events have increased over the West African Sahel. The increasing frequency of heavy rain events, can negatively affect the lowland crops’ growth and production. Two-season field experiments were conducted near Ouagadougou (Burkina Faso) to test the effects of temporary flooding and surface water stagnation on maize (Zea mays L.) growth and productivity. The treatments were organized into a split-split plot design. Three factors were monitored, including aboveground flooding levels (i.e., 0 cm, 2–3 cm, and 7–8 cm), flooding duration (i.e., three days and six days), and growth stages (i.e., six-leaf stage (V6), tasseling stage (VT) and milky stage (R3)). Optimal crop management was practiced to Obatanpa cultivar planted during the rainy season and flooding was induced by over-irrigation. The results show that three days and six days of flooding, reduced grain yield by at least 35% when they occurred at the tasseling stage. Only 4–6 days of flooding reduced grain yield by 21% at the six-leaf stage. Further scrutiny, using the stress day index (SDI), revealed that the penalty on yield increases exponentially under flooding conditions as the value of the stress day index increases. Considering the new characteristics of the rainfall regime in the West African Sahel, dominated by a high frequency of heavy rain events and wet spells, temporary floods, and water stagnation are tremendously contributing to yield loss of on-farm maize. As the region’s climate changes, we hypothesize that excess water stress will become the next cause of food insecurity in the area.

Effect of excess soil water on the development of Bermuda grass (Cynodon spp.)

ABSTRACT Soil drainage is an important technique in the construction of a sports lawn and information about the sensitivity of the crop to excess water influences the design of the project. Assuming that excess water affects the development of the grass and that the indices SEW30 (Sum of Excess Water above 0.30 m depth) and SDI (Stress-Day Index) are sensitive to the variables of development of the crop, the objective was to identify the sensitivity of Bermuda grass to the excess of water. The experimental design was completely randomized with five treatments and four repetitions. The treatments consisted of groundwater elevations: 0 cm d (at the level of the drains - control); 180 cm d (at 0.20 m from the soil surface); 270 cm d (at 0.15 m from the soil surface); 360 cm d (at 0.10 m from the soil surface); and 450 cm d (at 0.05 m from the soil surface), carried out fortnightly, lasting three days. The variables used to test the treatment were root length, photosynthesis rate, dry mass of roots, stolons, rhizomes, culms and leaves and dry mass of grass clippings. Stress caused by excess water near the soil surface reduced root length, dry mass of culms and leaves, and photosynthesis rate; Bermuda grass was more sensitive to excess water in its initial vegetative stage, which occurs until 42 days after planting; and the photosynthesis rate in the treatment with highest stress level decreased by approximately by 2/3 when compared to the condition of no water table.

Improved Empirical Representation of Plant Responses to Waterlogging for Simulating Crop Yield

Waterlogging causes apparent reductions in crop yields around the world. Crops undergo plant responses and adaptations due primarily to the reduction in soil oxygen concentrations in the plant root zone that occur during waterlogged conditions. Current methods of assessing and quantifying crop yield reductions due to waterlogging, such as the sum of excess water (SEW) and stress day index (SDI) accumulating methods, and the models DRAINMOD, Agricultural Production Systems Simulator (APSIM), and Salt Water And Groundwater MANagement (SWAGMAN) Destiny (Destiny) do not include plant physiological adaptation processes that may limit or avoid reductions in crop yield. This paper analyses results from field trials to create a unifying concept that recognizes the various responses and adaptations of crops to waterlogging. We propose an empirical three stage representation of crop responses and adaptations during waterlogging. Stage one represents increased plant function with unlimited water and adequate soil oxygen concentrations for root respiration for up to 3 d. Stage two follows and represents plant response to declining soil oxygen concentrations often resulting in decreased plant function. Finally, stage three represents species dependant plant adaptations. We test the sensitivity of SWAGMAN Destiny using our three stage empirical representation to estimate yield reductions due to waterlogging. Results are consistent with field trial observations, with decreased yield compared to simulations using 10% air‐filled pore space as the waterlogging criteria. We suggest the three stage empirical representation for specific crops can be used to improve simulation model estimations of crop yields due to waterlogging.

Response of Millet and Sorghum to Water Stress in Converted Poorly Drained Paddy Soil

Millet and sorghum are major dryland cereal crops, however their growth and productivity is limited by soil water stress with varying intensity. The major objective of this study was to evaluate water stress of millet and sorghum yield under drainage classes of poorly drained soil and to test the effect of the installed pipe drainage in poorly drained paddy soil to minimize crop stress. The research was carried out in poorly drained paddy fields located at alluvial slopping area resulting in non-uniform water content distribution by the inflow of ground water from the upper part of the field. Stress Day Index (SDI) was determined from a stress day factor (SD) and a crop susceptibility factor (CS). SD is a degree of measurement by calculating the daily sum of excess water in the profile above 30cm soil depth (<TEX>$SEW_{30}$</TEX>). CS depends on a given excess water on crop stage. The results showed that sum of excess water day (<TEX>$SWD_{30}$</TEX>) used to represent the moisture stress index was lower on somewhat poorly drained soil compared with poorly drained soil on 117 days. CS values for sorghum were 57% on <TEX>$3^{rd}$</TEX> leaf stage, 44% on <TEX>$5^{th}$</TEX> leaf stage, 37% on panicle initiation, 23% on boot stage, and 16% on soft dough stage. For proso millet CS values were 84% on <TEX>$3^{rd}$</TEX> leaf stage, 70% on <TEX>$5^{th}$</TEX> leaf Stage, 65% on panicle initiation, 53% on boot stage, and 28% on soft dough stage. And for foxtail millet the values were 73% on <TEX>$3^{rd}$</TEX> leaf stage, 61% on <TEX>$5^{th}$</TEX> leaf stage, 50% on panicle initiation, 29% on boot stage, and 15% on soft dough stage. SDI of sorghum and millet was more susceptible to excess soil water during panicle initation stage more poorly drained soil than somewhat poorly drained soil. Grain yield was reduced especially in proso millet and Foxtail millet compared to Sorghum.

배수불량 경사지 논에서 배수개선에 따른 콩의 수분스트레스 반응해석

There are considerable areas of wet paddy fields in Korea that requires improvement of its drainage system. In poorly drained sloping paddy fields, upland crops can be damaged by either rainfall or capillary rise of the water table caused by percolating water beneath the upper fields during summertime rainy season. The purpose of this study is to evaluate excess water stress of soybean yield by drainage systems. Four drainage methods namely open ditch, vinyl barrier, pipe drainage and tube bundle were installed within 1-m position at the lower edge of the upper paddy fields. Stress Day Index (SDI) approach was developed to quantify the the cumulative effect of stress imposed on a soybean yield throughout the growing season. SDI was determined from a stress day factor (SD) and a crop susceptibility factor (CS). The stress day factor is a measure degree and duration of stress of the (SEW30). The crop susceptibility factor (CS) depends of a given excess water on crop stage. The results showed that SDI used to represent the moisture stress index was most low on the pipe drainage 64.75 compared with the open ditch 355.4, vinyl barrier 271.55 and tube bundle 171.55. Soybean grain yield increased continuously with the rate of 3% in Vinyl Barrier, 32% in Pipe Drainage and 16% in Tube Bundle.

Scheduling irrigations for summer groundnut (Arachis hypogaea)

An experiment was conducted at Bilaspur during summer seasons of 1994 and 1995 to study the effect of irrigation levels on kernel yield, nutrient uptake and oil yield of groundnut (Arachis hypogaea L.). Irrigating summer groundnut at an 0.8 IW : CPE ratio (irrigation at 75 mm CPE) gave significantly higher podslplant, kernel yield and oil yield and resulted in higher uptake of N, P and K by the plants over 0.6 IW :CPE ratio (irrigation at 100 mm CPE). Irrigations scheduled under 1.0 and 1.2 IW :CPE ratio had no further advantage over an 0.8 IW :CPE ratio. Stress-day index concept proved useful to schedule irrigation in summer groundnut. Water-use effi- ciency (WUE), net and additional returns and input:output ratio were highest with an 0.8 IW :CPE ratio irrigation schedule.

STRESS DAY INDEX MODELS TO PREDICT CORN AND SOYBEAN RELATIVE YIELD UNDER HIGH WATER TABLE CONDITIONS

ABSTRACT High water table conditions reduce crop yields. This study developed com and soybean relative yield models for high water table conditions. The relative yield models were based on Stress-Day-Index (SDI) relationships using SEW30 (0.3-m water table depth) to describe the high water table stress criteria and normalized SDI crop susceptibility (CS) factors. The normalized crop susceptibility (NCS) factors were determined from previous studies conducted in North Carolina. The models were developed using existing field data for SDI and crop yield from Ohio. The resulting com model was tested against data from India and North Carolina and explained 69% of the relative yield variance for the pooled data. The soybean model explained 66% of the variance in relative yield for six years of soybean data from Ohio. The models developed should improve relative yield estimates using DRAINMOD, a water table management simulation model.

Crop Susceptibility Factors for Corn and Their Effect on Stress-Day Index

ABSTRACT Field data on crop susceptibility factors (CS) and stress-day factors (SEW30) were reviewed and evaluated. The effects of CS factors and their corresponding values of normalized crop susceptibility factors (NCS) on the relationship between stress day index (SDI) and relative yield (RY) were evaluated. Different sets of CS and NCS values for corn, obtained from different locations in the world, were also compared. The results of this study indicate that the relationships developed between SDI and RY by using CS factors will be significantly different from the ones developed by using the corresponding NCS factors. Also, the use of CS values from other locations could be acceptable for calculating the SDI values for drainage design if local data on SEW30 factors are available.

Stress-Day Factor and Stress-Day Index as Indicators of Drainage Needs of Soils

ABSTRACT FIELD data on water-table depths, plant parameters, and corn yields were collected for 3 years (1984 through 1986) on the Clarion-Nicollet-Webster Soil Association from 50 plots under naturally fluctuating water-table conditions. The stress-day factor (SEW30) and stress-day index (SDI) concepts were used to provide a quantitative means of determining drainage needs of soils. Corn yield and SDI were used to assess the crop production losses due to excessive wetness in the soils. The stress-day factor and index were found to be useful tools in evaluation of drainage needs of poorly drained soils. The highest values of SEW30 and SDI were obtained for naturally very poorly drained soils, while naturally well-drained soils gave about zero values of SDI. Significant differences were found in SEW30 and SDI between all natural drainage classes of soils. This study also showed a strong relationship between relative yield and SDI for corn. This relationship was compared with published data from three other sources -India, North Carolina, and Ohio and found to be in agreement. The information in this paper on transient waterlogging's effect on crop growth under different natural soil drainage regimes should provide a basis for improving the design of field drainage systems.

Excessive Soil Water Effects at Various Stages of Development on the Growth and Yield of Corn

ABSTRACT THE response of corn to naturally fluctuating water tables at five different stages of growth was studied for 3 years. Fifty plots of 15 m x 15 m were established in 1984 on Nicollet soil in an area that is not artificially drained. In the center of each plot, an observation well was installed for water-table measurements. Water-table hydrographs were developed for each plot annually to quantify crop stress factors from excessive wetness (SEW30, a summation of days times the height of the water table above 30 cm). The results of these studies indicate that SEW30 values of as low as 40 cm-days in the early part of the growing season can significantly reduce corn yields. Corn yields decreased linearly with the increase in SEW30 values and the Stress Day Index (SDI). Lower corn yields resulted from both decreased plant population and poor crop growth due to excessive wetness.

Predicting the effects of drainage systems on corn yields

Stress day index (SDI) models were incorporated in the water management simulation model, DRAINMOD, to quantify the effect of soil water stresses on corn yields. The effects of a combination of excessive and deficient soil water conditions were approximated by a simple first-order crop response model, YR = YRw × YRd, where YR is the overall relative yield, and YRw and YRd are the relative yields due to excessive and deficient soil water conditions, respectively. The accuracy of the modified water management model was evaluated by comparing predicted and measured corn yields for 16 plot years of experimental data on the Tidewater Research Station near Plymouth, NC. The predicted and measured results were in good agreement with the model describing 63% of the variation in yields for the 12-year period. Use of the modified water management model was demonstrated by simulating the performance of several drainage system designs for a Portsmouth sandy loam soil. The results of the simulation show that a maximum long-term relative yield of 80% of the potential corn yield can be obtained with a drain spacing of 40 m or less with good surface drainage. Higher yields could not be obtained without irrigation to reduce deficit soil water conditions. The response of long-term average corn yields to surface drainage varies inversely with the intensity of subsurface drainage. The 25-year average yield for 100 m spacing was only 47% of the potential yield when the surface drainage was poor as compared to 61% of potential yield for good surface drainage.

Corn Yield Response to Excessive Soil Water Conditions

ABSTRACT DATA from a long-term field drainage experiment in Ohio were analyzed to develop a relationship be-tween relative yield and stress day index (SDI). The water management model, DRAINMOD, was modified to compute SDI for four treatments for each of the 12 yr of the experiment. Relative yields were obtained for each case by dividing the measured yield by the potential yield. Results of the study showed that there is a strong rela-tionship between relative yield and stress day index for corn. A linear regression line was fitted to the data and the regression model was tested against three other sets of data from the literature two from India and one from Iowa. The model was in good agreement with results from the independent experiments even though there were wide differences in soils, climate and experi-mental conditions. Statistical tests showed that relation-ships for relative yield vs. SDI, obtained from the four in-dependent experiments, were from the same population, and that the Ohio regression model could be used for all conditions considered.

Incorporating Crop Needs into Drainage System Design

ABSTRACT AN approach is proposed for incorporating crop drainage requirements into drainage design pro-cedures. The overall methodology links crop drainage re-quirements, climatological data, and drainage theory in-to a workable design method through incorporation of the stress-day index concept into the NCSU water management model.

Choice of Irrigation Timing Indicator for Narrow Row Cotton1

AbstractThis irrigation study was undertaken to compare water use efficiencies (WUE) resulting from three methods of timing water applications on narrow‐row cotton (Gossy‐pium hirsutum L.). Irrigation timing during the 1971 and 1972 growing seasons was accomplished using the soil water potential (SWP)‐fixed level, leaf water potential (LWP)‐fixed level, and stress day index (SDI)‐vari‐able level of LWP, based on crop sensitivities, as indicators. Specific levels of each indicator were selected so that nearly identical yields would result for all three timing indicators, thus making possible the valid comparison of WUE. With the SWP indicator as a basis for comparison, higher WUE were obtained with the LWP and SDI indicators in both years. At a plant population of 150,000 plants/ha, average increases in WUE (seed cotton yield divided by irrigation plus rainfall amounts) were 17 and 38% for the LWP and SDI indicators, respectively. Average increases when WUE was calculated as yield divided by irrigation amount only were 30 and 82%, respectively. The increases in WUE were due to reductions in irrigation amounts rather than increases in yield. These results demonstrate that significant benefits in stretching irrigation water supplies are possible when using plant‐based measurements and when plant sensitivities at different growth stages are quantitatively considered in timing irrigations.