Cm Of Rainfall Research Articles

Flowering Crab, Control of Fall Webworm, Wooster, Ohio, 1990

Abstract Flowering crabapple trees, 2-4 m tall, growing in a research plot at the OSU/OARDC campus, were used to evaluate efficacy of selected insecticides against fall webworm larvae. Twigs having small tents were removed, 4 Sep, from Mortis in Allen Co., OH, placed in plastic bags and transported to Wooster in coolers. Tents were attached to Malus trees with a Twistee at the OARDC research plot. A KWH backpack mistblower, operating at half-throttle on aperature setting # 3 for 30 sec, was used to deliver about 600 ml of finished spray to each tree. Sprays were directed toward the web and surrounding foliage on each of 3, single-tree replicates per treatment. Sprays were applied 8 Sep when conditions were cloudy, 21°C, with 0-8 km/h winds. There were 2.5 cm of rainfall in the experimental area during the test period. Treatment effectiveness was evaluated 5 DAT by dismantling each web and assessing larval condition.

Nitrate Leaching under Irrigation on Coastal Plain Soil

The effect of irrigation and nitrogen management on ground-water quality was evaluated for four years on a Sassafras sandy loam Coastal Plain soil. Applying the greatest portion of the nitrogen by side-dressing and by fertigation were compared. Maintaining optimum soil moisture and partial irrigation (applying one half the water as optimum irrigation) were the water management practices investigated. Nitrate concentrations increased in the ground water for all nitrogen and irrigation-management practices. The mass of the nitrate leached was related to the drainage volume. In all but one year the largest mass of nitrate was leached during the fall and winter months, when the largest amount of recharge occurs. Very little nitrate was leached during the growing season for any nitrogen or irrigation management practice except for one year when 30 cm of rainfall occurred in August. The mass of nitrate leached during that growing season ranged from 33.9 kg/ha for partial irrigation to 139.0 kg/ha for full irrigation.

Birch, Control of Birch Leafminer, Wooster, Oh, 1989

Abstract Birch suckers, 1-1.5 m tall, growing at the base of selected birch at an OARDC experimental plot under nursery management conditions, were used to evaluate efficacy of selected insecticides against birch leafminer. A C02 compression sprayer at 40 psi with a single Teejet SS8004 flat-fan nozzle was used to apply sprays to run-off. Sprays were applied 18 May under sunny skies, 21°C, and 8-16 km/h winds. The treatment area received 6 cm of rainfall during the test period. Only suckers with adult birch leafminer activity were selected; sprays were applied to each of 4 replicates/treatment. Treatment effectiveness was evaluated 12 DAT by counting the number of mined leaves of the 10 most apical leaves on 4 sucker twigs from each replicate.

Elm, Cherry, and Mulberry, Efficacy of Selected Insecticides Against Fall Webworm, Wayne Co., Ohio, 1989

Abstract Elm, cherry, and mulberry, 2-4 m tall, growing along roadsides were used to evaluate insecticides against fall webworm when larvae were 15-25 mm long. A KWH backpack mistblower operating at half throttle on aperature setting # 3 for 30 s, was used to deliver 600 ml of finished spray/tree. Sprays were applied 19 Sep under sunny skies, 23°C, and 8-16 km/h winds. The treatment area received 4.3 cm of rainfall during the test period. Sprays were directed toward the web and surrounding foliage on each of 3 single-tree replicates. Evaluations were made 6 DAT by dismantling each web and counting live and dead larvae.

Cotoneaster, Tropical and Foliar Spray Applications Evaluated Against Japanese Beetle Adults, Wooster, Ohio, 1989

Abstract Cotonester growing in 1-gal (3.9 1) containers were used to evaluate selected insecticides against Japanese beetle adults. A COa compression sprayer at 20 psi with a single Teejet SS8004 flat-fan nozzle was used to apply sprays to runoff. Topical and foliar sprays were applied 18 Jul under sunny skies, 29°C, and 16-24 kph winds. Plants were watered by hand every Mon, Wed, and Fri and received 5 cm of rainfall during the test period. Treatment procedures were as follows; TOPICAL—3, 10-15 cm twigs were placed upright in culture tubes with the cut end in water to keep sprigs fresh. Five, field collected adults were placed on each twig, and sprays were applied. Adults and twigs were immediatly transferred to 1-liter fonda containers fitted with mesh tops. Treatment effectiveness was evaluated 48 h later by assessing beetle mortality. FOLIAR—2, 10-15 cm twigs were removed from each of the 3, single-plant replicates/treatment, at specified intervals after spraying, and, along with 5 field collected adults, were placed in 1-liter fonda containers with mesh tops. Residual efficacy of insecticides was evaluated 1, 3, 7, and 14 DAT by allowing adults to feed on treated foliage for 48 h. After 48 h, moribund adults were placed on untreated foliage, and final percent mortality was assessed 48 h later.

Residual Activity of Insect Growth Regulators, 1989

Abstract On 19 Jun, treatments were applied to four small (5 ft) ‘Red Yorking’ apple trees maintained outside via a handgun to drip. Beginning on the day of application, and once a week for 4 wk afterward, 4 leaves from each of the treatment’s 2 trees were randomly sampled with 2 leaf disks (17.9 mm diam) cut from each leaf. Each pair of leaf disks was placed inside a 7.5 × 29.6 mm glass shell vial. Five neonate TABM larvae were then placed inside the vial. TABM larvae were obtained from a laboratory colony reared on a lima bean artificial diet. Vials were kept in a growth chamber set at 20°C with a 16L:8D photoperiod. Seven days later the larvae were examined for mortality. Each treatment had 40 larvae assayed weekly (8 vials with 5 larvae/vial). This process was continued up to 28 days (17 Jul) after the trees were initially treated. During the 28 days that the treated leaves were exposed to weathering, measurable rain occurred on 16 d, for a total of 22.9 cm of rainfall. The average temperature during this period was 23.1°C.

Water Relationships of Claypan and Constructed Soil Profiles

AbstractClaypan soils with poor physical properties are the only surface materials available to cover and reclaim much of the spoil left by strip mining for coal in east‐central Texas. We compared an undisturbed claypan soil profile of Axtell fsl fine montmorillonitic, thermic Udertic Paleustalfs) to four constructed soil profiles and evaluated them as cover soils for toxic minespoil. We compared profiles constructed from minespoil selected for low pyrite content alone (non‐topsoiled) against the same selected spoil covered by a mixture of Axtell soil material. The rainfall intake rate and physical properties of the materials controlled forage production by kleingrass (Panicum coloratum L.). All of the constructed soils stored less water in the soil profile than the undisturbed claypan soil, and forage yield was reduced on them during drought. Infiltration rate during the first 2 cm of rainfall influenced forage yield more than final intake rate. Mulch application increased water storage and forage yield up to 15% on selected minespoil, but not on the mixed claypan soil profiles. Either selected minespoil or a mixture of Axtell soil may be used to cover toxic random soil with a nontoxic layer, but the Axtell mix had the least acid‐forming potential. Selected minespoil material was equal in value to a mixture of the 1.8 m claypan soil profile as a surface material for constructed minesoils.

Iso-erodent map of Zambia: Part II: Erosivity prediction and mapping

Using the data of the rainfall data bank, as presented in part I (this volume), the monthly erosivity has been calculated as a function of average monthly rainfall, average number of days with at least 0.1 cm of rainfall, and the average maximum daily precipitation per month. The model based on multiple linear regression resulted in the best correlation. 257 Zambian rainfall recording stations were selected to predict and to map the erosivity. All rainfall parameters used were averaged over a period of at least 10 years. Efforts were made to ensure that the selected stations were as much as possible evenly spread over the country. The selected erosivity prediction model was used to calculate the erosivity of the stations. Finally, the annual erosivity in terms of Kinetic Energy and of two indices were mapped on a 1 7 000 000 scale. The iso-erodent maps were divided in seven erosivity zones. In Zambia, the annual EI 30 index (WISCHMEIER 1959) is ranging from 259 to 1157 with an overall mean of 720 Jm −2h −110 2. The annual Kinetic Energy, calculated according to KINNELL (1981), is ranging from 10 394 to 27 102, showing a country average of 18 519 J m −2. The ΣN p I p index (LAL 1976) is ranging from 131 to 423 with a country mean of 280 cm 2 h −1.

Release of hexazinone from pronone 10g granules exposed to simulated rainfall under laboratory conditions

Abstract The release of surface coated hexazinone, 3‐cyclohexyl‐6‐(di‐methylamino)‐1‐methyl‐1,3,5‐triazine‐2,4(1H,3H)‐dione, from a new granular formulation, PRONONE 10G, was tested under simulated rainfall. The release of hexazinone from PRONONE 10G granules treated with 1.3, 2.5 and 5.1 cm of rainfall were 65.5, 87.4 and 91.5 % with CV of 8.7, 2.9 and 5.4 %, respectively. Comparing with the conditions tested in this laboratory study, the amount of rainfall required for a 90% release of hexazinone under field conditions is estimated to be less than 5 cm of intermittent rain complemented with overnight dew over a period of time. Based on a sample of the PRONONE 10G formulation, a single granule weighed 20.9 mg (11% CV, n = 600) and contained 10.7% hexazinone (15.6% C.V.), 7% higher than the label 10% hexazinone content of this granular formulation.

Tilted‐bed Simulation of Erosion and Chemical Runoff from Agricultural Fields: II. Effects of Formulation on Atrazine Runoff

AbstractThe concentrations and loads of atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] in runoff water from “tilted‐bed” soil trays under intense simulated rainfall were similar to losses reported in field studies. Atrazine was applied at rates of 2.7 to 3.4 kg/ha as emulsion, wettable powder, dispersible liquid, and dispersible granule formulations, on a loam soil in eight 2.2‐ by 1.2‐m trays tilted to 1.3% slope. In simulated storms in which 3 cm of rainfall fell in 5 min and generated 0.7 cm of runoff, total atrazine losses ranged from 4 to 8% for the emulsion and dispersible‐liquid applications and 9 to 12% for the dispersible‐granule and wettable‐powder formulations. One‐fifth of the total losses occurred in the first liter of the runoff. This initial “flush” loss of atrazine in the water front resulted in concentrations up to 23 mg/L in the first runoff depending on the differing particle sizes of the spray deposits of the different atrazine formulations. The tilted‐bed/rainfall simulator system appears to offer promise as an inexpensive and convenient supplement to field experiments for characterizing pesticide movement or yield in runoff and evaluating the potential of new chemicals for nonpoint source pollution.

Effects of Residue Cover on Pesticide Losses from Conventional and No-Tillage Systems

ABSTRACT MOVEMENT of atrazine and 2,4-D in runoff and sediment v^as measured on twelve field plots under simulated rainfall. The plots were divided into conventional and no-tillage systems. Within each tillage system, three residue levels (0, 750, and 1500 kg/ha) were studied. Simulated rainfall was applied to the plots three times at a rate of 5.08 cm/hr for a total of 10.2 cm of rainfall. Runoff and sediment losses were found to increase with decreasing residue cover for both tillage systems. No-till reduced sediment loss and total runoff volume by 98 and 92%, respectively, compared to conventional tillage. Concentrations of atrazine and 2,4-D in runoff and sediment were greater from the no-till plots than from the conventional plots but total losses were less. Water was the major carrier for both herbicides, although the concentration of 2,4-D in sediment was higher than that of water. Averaged over all plots, the atrazine losses were 2.9% of applied amount for conventional tillage and 0.3% for no-till. The corresponding values for 2,4-D were 0.3% and 0.02%.

Non‐stomatal limitation of CO2 assimilation in three tree species during natural drought conditions

The effect of drought on CO2 assimilation and leaf conductance was studied in three northern hardwood species: Quercus rubra L., Acer rubrum L. and Populus grandidentata Michx. Leaf gas exchange characteristics at two CO2 levels (320 and 620 μl I−1) and temperatures from 20 to 35°C were measured at the end of a dry period and shortly after 10 cm of rainfall. The effects of drought varied with species, temperature and CO2 level. Calculated values of internal CO2 concentration showed little or no decline during drought. Differences in assimilation, before vs after the rains, were most apparent at the higher CO2 level. These latter two observations indicate nonstomatal disruption of CO2 assimilation during the dry period. In P. grandidentata there was a substantial interaction between drought and temperature, with a resultant shift in the temperature for maximum assimilation to lower temperatures during drought. During drought, internal CO2 concentrations increased sharply in all three species under the combined conditions of high temperatures and the higher CO2 level.

Rainfall, agriculture, livestock and human density in the dry regions of Kenya

Models based on empirical data are produced to predict the human carrying capacity of semi-arid and arid Kenyan districts from rainfall and the resulting crop and livestock yields. These models predict a carrying capacity ranging from 1–2 persons/km2, depending on livestock in the driest districts, to about 200 persons/km2 depending on maize and beans at the upper limit (76 cm) of the semi-arid zone, based on the assumption that the average long-term rainfall is received every year. If the long-term carrying capacity is defined by the smallest annual rainfall received over a 10 year period the predicted human populations is lowered to about 70 persons/km2 for areas receiving a long-term average of 76 cm of rainfall per year. Below 38 cm average annual rainfall, the population must depend totally on livestock production, which is less sensitive to rainfall but permits only low human populations. In semi-arid crop growing areas the maximum human populations observed are at or below the carrying capacity predicted from the average annual rainfall but are at or above the carrying capacity based on a one in ten year low annual rainfall level. The lack of detailed empirical data is noted, and important topics for research are suggested.

Detecting infiltration of water through soil cracks by time-domain reflectometry

During an experiment where simulated rainfall was applied to cracked soil, time-domain reflectometry (TDR) was used to measure the water content of cracks and adjacent soil vs. water content at some distance from the cracks. At a depth of 10 to 30 cm the rate of wetting of soil immediately adjacent to the cracks was more rapid than thatof the soil at some distance from the cracks. Independent predictions of when water should begin flowing down the cracks were deduced from knowledge of the applied “rainfall” rate, field-measured hydraulic conductivity, initial water content and bulk density. These predictions checked well with those TDR measurements which indicated when water began to accumulate in and adjacent to the cracks in a clay soil under corn and soybeans. More than 1 cm of rainfall at rates greater than 0.1 cm/h contributed water to the soil cracks. The water content profiles showed the very limited depth of wetting in the soil at some distance away from the cracks as opposed to the much greater depth of wetting within and adjacent to the cracks.

Species Composition and Diversity of Macroinvertebrates in Two Playa Lakes on the Southern High Plains, Texas

Species Composition and Diversity of Macroinvertebrates in Two Playa Lakes on the Southern High Plains, Texas

Water Requirement for Sugarcane Production

ABSTRACT SIX lysimeters were used to control water tables at 30, 60, and 90 cm below the muck soil surface for sugar-cane culture. An evaluation of effective rainfall showed that about 3.4 cm of rainfall was stored in the soil for each 100 cm increase in water table depth. More water was required in the dry season and grand growth period for a high water table than for a low water table. Water required to produce 1 kg of cane varied from 89 to 118 kg.

Hard Red and Durum Spring Wheat Responses to Seeding Date and NP‐Fertilization on Fallow1,2

AbstractWith recent development of high‐yielding semidwarf hard red (Triticum aestivum L.) and medium‐height durum (T. turgidum L.) spring wheats, information voids have been created in the management guidelines needed to obtain optimum production. Our objective was to determine if the two wheat types, planted at the same rate and seeding depth, would respond similarly to NP‐fertilization and to early, medium, and late seeding dates. The soil at both field sites was a Williams sandy loam (fine‐loamy, mixed, Typic Argiborolls). Although grain yields were nearly two times greater with 25.1‐cm rainfall at Culbertson than with 17.2 cm of rainfall at Outlook, the two speciesof wheat responded similarly to seeding dates and fertilization. Applying N and P, each at 45 kg/ha, significantly increased grain yields 30 to 60% at both sites. With adequate P‐fertilizer, ammonium nitrate and urea increased grain yields of both varieties similarly on all three seeding dates.Based on the results of this study, both types of wheat responded positively to early seeding and NP‐fertilization, so there would be no need to prepare separate production and fertilizer management guidelines for each wheat species. Grain yield increases from NP‐fertilization were greater for both types of wheat for the early and medium seeding than for the late seeding date.

Nitrogen-water Relationships of Onions Grown on Organic Soil1

Abstract Field experiments were conducted on organic soil for 2 years to evaluate the influence of frequent irrigation and topdressings with N on growth, maturity and storage life of onions (Allium cepa L.). With no irrigation, growth to midseason, maturity, and final yield were not influenced by increasing amounts of N. The growth to midseason, and the final yield increased and maturity was earlier with increasing amounts of N applied to onions receiving 5 cm of rainfall + irrigation per week. Sprouting in storage was earlier with high N and latest with no N or with the low N rates. The effect was greater with irrigation. Onions did not respond to N topdressing without irrigation even though rainfall was regular. With irrigation, the highest yield and earliest maturity was obtained with 22 or 34 kg of N/ha applied whenever the crop received 10 cm of water. No advantage in yield or maturity was obtained by applying N after mid-July. Maturity was earlier without irrigation regardless of N treatment.

Potential effects of acid precipitation on soils in the humid temperate zone

Unmanaged soils in the northeast United States generally tend toward increasing acidity which results from several natural processes in the soil. Possible effects of acid precipitation on these processes may be caused by hydrogen ions associated with excess anions in the precipitation and, in addition, the anions may also have specific effects. This is especially true for N and S both of which have important biological implications. It is likely that direct effects of the H ion will be modest. As an example, the acidity in 114 cm of rainfall per year (Connecticut's average) with a pH of 4.3 would require 28.5 kg ha −1 of limestone for neutralization. By contrast agronomic practice in Connecticut frequently dictates limestone additions as high as several thousand kg ha−1 to neutralize acidity generated by a combination of natural processes and fertilizer amendments. Studies of rainfall composition in Connecticut from 1929 to 1948 showed no clear trends with time and indicated levels of sulfate and nitrate in rainwater similar to those reported today. In a 10 yr lysimeter study in Connecticut in which tobacco was grown using conventional fertilization techniques, soil pH decreased from 5.4 to 5.0 and both gains and losses of soil cations were recorded. Thus it appears that changes in unmanaged soils induced by acid precipitation alone will be modest and subtle and probably cannot be expressed completely by measuring changes in soil pH value.

Nitrogen Movement Comparisons in Cropped versus Fallowed Soils1

AbstractThe movement and accumulation patterns of N, applied as KNO3 to cropped and fallowed plots, were studied on two widely different soils, Marlboro and Davidson. Generally, the movement and accumulation patterns indicated movement of N to a greater depth and extent on the cropped than on fallowed plots. Nitrogen movement in the Marlboro surface and subsoil was considerably greater than in Davidson soil. Even with excessive rainfall, most of the N recovered 11 to 12 months after application was concentrated between the 46 to 122‐cm depths with the largest accumulation occurring in the 61 to 91‐cm layer. After 10 weeks and 29 cm of rainfall, 78% of the applied N was recovered on the fallowed Davidson soil while after 50 weeks and 154 cm of rainfall 53% was recovered. Comparable recoveries for the cropped plots were 89 and 49% respectively. After 5 weeks and 12 cm rainfall, the recovery on the fallowed plots of the Marlboro soil was 109% but had decreased to 33% after 46 weeks and 124 cm of accumulated rainfall. Data for cropped plots indicated 119 and 25% recovery for the respective sampling periods. Recovery increased approximately 5 to 10% on the cropped plots when the plant N uptake values were included.