Tillage Corn Research Articles

Water consumption of corn under different methods of primary tillage after row-crop predecessors on an energy-storage soil maintenance system

The object of research was the light chestnut soil of the Chokh Agrofirm of the Gunibsky district in the Kizilyurt transhumance zone of the Republic of Dagestan. The humus content in the arable layer is 2.77%, P2O5–2.21, K2O – 32.8 mg/100 g, the density of the arable soil layer is 1.24 g/cm3, the lowest moisture capacity (MC) is 29.2% (layer 0–0.6 m). The effectiveness of two row-crop predecessors was studied: sunflower for seeds and corn for grain, and the use of skimmers in the main tillage for corn. Soil moisture, watering and irrigation standards, incoming and outgoing items of the water balance and the coefficient of water consumption for corn were determined. In the second ten days of May, the plant remains of predecessors were crushed using double disking with heavy disc harrows BDT-3, plowing was carried out to a depth of 0.28–0.30 m with a PLN-4-35 plow with and without skimmers, the field was leveled with a small leveler MV – 6 and watered at the rate of moistening the soil layer of 0–0.6 m in strips with lateral release of water manually, vegetation irrigation was carried out in furrows. Sunflower sowing was carried out with seeds of the VNIIMK-8883 variety, corn – hybrid ROSS-299, the seeding rate for both crops was 72 thousand seeds/ha. Fertilizers for sunflower were applied at the rate of N90Р40К90, including N40Р24К74for plowing, N16Р16К16– when sowing with seeds, N34for fertilizing in the phase of 5–6 leaves when cutting furrows, for corn – N90Р40, of which N40Р24for plowing, N16Р16К16when sowing with seeds, N30in fertilizing in the phase of 3–5 leaves. It has been established that in the areas of irrigated agriculture of the Western Caspian region, when selecting row-crop predecessors for corn for grain, preference should be given to early-ripening varieties of sunflower for seeds, which are harvested in the third decade of July, and after harvesting it remains in the soil more than 15 t/ha of plant mass. At the same time, the maximum corn yield is achieved – 9.16 t/ha of grain, exceeding the control by 33.1%, due to which, with the same total water consumption as the control option, the water consumption coefficient is reduced by 23.7%.

Method of corn contamination decreasing after later harvesting predecessors under energy-storage soil maintenance system in irrigation landscapes

The research was carried out at Agrofirm Chokh of the Gunibsky district in the Kizilyurt transhumance zone of the Republic of Dagestan on light chestnut soil. The humus content in the arable layer is 2.77%, P2O5 – 2.21, K2O – 32.8 mg/100 g of soil, the density of the arable layer is 1.24 g/cm3, the lowest moisture capacity (MC) of the soil layer 0–0.6 m is 29.2%. We studied the influence of two corn predecessors: sunflower and corn itself during the main tillage for corn based on plowing to a depth of 28–30 cm without skimmers and with skimmers. During the autumn period, after harvesting the predecessors, the soil was not cultivated, and in the spring, upon the onset of its physical ripeness, two treatments were carried out in a layer of 0–15 cm with disk cultivators to crush the plant residues of the previous crop and plowing to 28–30 cm with a PLN-4-35 plow when physical ripeness of the soil in this layer. It has been established that a radical way to reduce the weediness of corn crops and increase its yield in the irrigated conditions of the Western Caspian region when placed after late-harvested predecessors, including repeated sowings in the same field, is to carry out basic tillage and moisture-recharging irrigation in the spring of the year of sowing. To chop the plant mass remaining after harvesting the predecessor, double processing with disc implements should be carried out before plowing. Plowing is carried out with skimmers, which ensure uniform distribution of weed seeds in the surface layer and their simultaneous germination at a later date than when plowing without skimmers. Subsequently, their life activity is limited to vegetative corn plants. The infestation of corn crops with such soil treatment is reduced three times, the corn yield for the predecessor corn increases by 1.12 t/ha of grain (16.3%), after sunflower – 1.32 t/ha (17.8%).

Features of cultivation of corn for grain on ordinary chernozem in the Karachay-Cherkess Republic

Corn grain is the most valuable in terms of nutritional value, digestibility and energy intensity. In the grain balance its share is 5–7 %, in the feed – 30–35 %. Today, corn is cultivated in 58 countries on an area of 138–141 million hectares. Corn plays a crucial role in the restoration and expansion of the fodder base. In recent years, due to the need to optimize labor and money costs when cultivating corn, it has become especially difficult to choose the right method of basic tillage for corn. Most authors who study the influence of tillage methods on corn yield believe that disking as the main tillage is inferior to plowing in terms of moisture retention and accumulation, the effect on corn yield and crop contamination. According to some data, one of the elements of corn cultivation technology that have an advantage are hybrids with increased drought resistance, cold resistance, resistance to lodging and fragility of the stem. The purpose of the work was to determine the features and improve the technology of cultivation of corn for grain on ordinary chernozem in the Karachay-Cherkess Republic. The objects of research are medium–ripened, medium-early and early-maturing hybrids DKS 3939, AC 201, Mashuk 171. In the conditions of the Republic the complex infl uence of tillage techniques – disking and plowing, as well as hybrids of foreign and domestic breeding on soil fertility and corn grain productivity was studied. The cultivation of corn hybrids in the zone of unstable moisture has proved a positive agronomic assessment of the treatment method – plowing, which is justified not only by the increase in yield, but also by its economic efficiency.

Preemergence herbicide premixes reduce the risk of soil residual weed control failure in corn

AbstractWidespread occurrence of herbicide-resistant weeds and more variable weather conditions across the United States has made weed control in many crops more challenging. Preemergence (PRE) herbicides with soil residual activity have resurged as the foundation for early season weed control in many crops. Field experiments were conducted in Janesville and Lancaster, Wisconsin, in 2021 and 2022 (4 site-years) to evaluate the weed control efficacy of solo (single site of action [SOA]) and premix (two or more SOAs) PRE herbicides in conventional tillage corn. Treatments consisted of 18 PRE herbicides plus a nontreated check. At the Janesville-2021 site, S-metolachlor + bicyclopyrone + mesotrione, atrazine + S-metolachlor + bicyclopyrone + mesotrione, and clopyralid + acetochlor + mesotrione provided >72% giant ragweed control. At the Janesville-2022 site, none of the PRE herbicides evaluated provided >70% giant ragweed control due to the high giant ragweed density and the lack of timely rainfall. At the Lancaster-2021 site, atrazine, dicamba, and flumetsulam + clopyralid provided <45% waterhemp control, but the remaining treatments provided >90% control. At the Lancaster-2022 site, the efficacy of some PRE herbicides was reduced due to the high waterhemp density; however, most herbicides provided >75% control. At the Lancaster-2021 and Lancaster-2022 sites, only dicamba and S-metolachlor did not provide >75% common lambsquarters control. Group 15 PRE herbicides provided >75% control of giant foxtail. Across weed species, PRE herbicides with two (78%) and three (81%) SOAs provided greater weed control than PRE herbicides with a single SOA (68%), indicating that at least two SOA herbicides applied PRE result in better early season weed control. The efficacy of the PRE herbicide treatments evaluated herein varied according to the soil seedbank weed community composition and environmental conditions (i.e., rainfall following application), but the premixes were a more reliable option to improve early season weed control in conventional tillage corn.

Effect of crimson clover on the critical period of weed control in conservation tillage corn

An increasing number of herbicide-resistant weeds, in addition to troublesome weeds, pose a significant challenge for chemical weed control in corn. Simultaneously, high-biomass cover crop adoption has gained popularity among farmers as an efficient weed control strategy. While the critical period of weed control (CPWC) following conventional tillage has been well documented, there is little knowledge of CPWC following high residue cover crops in corn. A two-year field experiment was conducted to estimate the influence of a high biomass crimson clover cover crop and conservation tillage on the critical period of weed control (CPWC) in corn. The experiment was implemented in a split-plot design in which the main plots were conventional tillage (CVT), conservation tillage following winter fallow (CT + WF), and conservation tillage following crimson clover (CT + CC), and the subplot included multiple durations of weedy plots (estimation of critical timing of weed removal (CTWR), i.e., beginning of weed control) and weed-free plots (estimation of critical weed-free period (CWFP), i.e., end of weed control). The results described that the estimated duration of CPWC in three systems, included CT + CC, CT + WF and CVT equals 2.8 weeks, 3.5 weeks, and 4.9 weeks respectively in 2019. In 2020, the predicted value of CTWR under CT + CC equals 3.8 weeks after planting and the predicted values of CWFP were 5.1 and 5.7 weeks after planting under CT + WF and CVT systems, however, the model did not predict some values within the fitted 8 weeks of time. In conclusion, the presence of a crimson clover cover crop delayed the CTWR and caused the early beginning of CWFP and hence shortened CPWC in 2019. During most of the growing season, weed biomass production was less under CT + CC plots than CVT and CT + WF systems of weedy treatment in both years. While weed biomass production fluctuated in CT + CC, CVT and CT + WF systems in weed-free treatment.

Real-world fuel-based and tillage area-based emission factors of agricultural machines during different tillage processes

Emissions of agricultural machines during tillage processes played an important role in severe seasonal pollution events in agricultural areas in China and cannot be ignored. In this study, the CO, NOX, HC and PM2.5 emissions of agricultural machines during real-world tillage processes were tested using a portable emission measurement system (PEMS), and their fuel-based and tillage area-based emission factors were calculated. The CO, NOX, HC and PM2.5 emissions were influenced by emission standards, engine rated power, tillage processes and crops. Only the CO, HC and PM2.5 fuel-based emission factors were reduced from China 0 to China II. For China III agricultural machines, the fuel-based emission factors were higher during plowing and tilling than during harvesting. The tillage area-based CO, NOX, HC and PM2.5 emission factors of corn tillage process were 11.85 ± 8.30, 53.21 ± 48.80, 3.46 ± 3.14 and 1.64 ± 1.33 kg/km2, respectively. The tillage area-based CO, NOX, HC and PM2.5 emission factors of wheat tillage process were 19.69 ± 21.50, 79.98 ± 63.22, 3.90 ± 2.96 and 1.61 ± 2.43 kg/km2, respectively. The tillage area-based emission factors of China III agricultural machines during plowing and tilling were higher than those during harvesting. The fuel consumption per unit tillage area can be used to provide a reference for the interconversion of the two emission factors in future studies. By comparing the fuel-based emission factors in this study with those in the Guidelines and other studies, we observed that the CO, HC and PM2.5 emissions of agricultural machines with corresponding emission standards may be overestimated and the NOX emissions may be underestimated in areas where wheat and corn are mainly grown. Moreover, the pollutant emissions of agricultural machines were regionally different. These results could help elucidate the pollution contribution of agricultural machines in China.

The effect of biological additive on the fermentation quality of whole-crop rye silage

The effect of biological additive on the fermentation quality of whole-crop rye silage

Long-term no-till increases soil nitrogen mineralization but does not affect optimal corn nitrogen fertilization practices relative to inversion tillage

No-till management is a proven practice for increasing soil organic matter in many environments. By increasing soil organic matter, no-till may increase soil N mineralization, potentially reducing crop demand for N fertilizer relative to inversion tillage. In this study, we hypothesized that, relative to inversion tillage (moldboard plowing), long-term no-till would: i) increase total N stocks, ii) increase mineralized N during the growing season, iii) increase grain yield and N uptake, and iv) reduce reliance of corn (Zea mays L.) on N fertilizer inputs. We tested these hypotheses in a long-term, continuous corn tillage and fertilizer N rate study located in Lexington, KY. We measured the total soil N and potentially mineralizable N after 48 years, the in situ mineralized N and N uptake during two corn seasons (2018–2019), and the corn grain yield for five seasons (2015–2019). We evaluated the effect of no-till on N fertilizer reliance in two ways – the first was by measuring the agronomic optimum N rate of corn in the two tillage systems, and the second was by measuring the corn yield response to late N fertilization timing in the two tillage systems. We found that the no-till system had 1000 kg N ha−1 greater total soil N stocks in the top 20 cm, mineralized 65 kg ha−1 more N during corn growth, and resulted in 22−71 kg N ha−1 and 780−1800 kg ha−1 greater N uptake and grain yield across N rates, respectively, than the plowed system. The agronomic optimum N rate (AONR) did not differ among tillage treatments, potentially because the no-till treatment yielded more and thus demanded more N. Although corn yield responded to the late N fertilization treatment, the response was similar in both the no-till and plowed treatments. We conclude that long-term no-till increases soil N mineralization and corn yield relative to inversion tillage, with minimal effect on the AONR or optimal timing of N fertilizer application.

Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016

After decades of declining cropland area, the United States (US) experienced a reversal in land use/land cover change in recent years, with substantial grassland conversion to cropland in the US Midwest. Although previous studies estimated soil carbon (C) loss due to cropland expansion, other important environmental indicators, such as soil erosion and nutrient loss, remain largely unquantified. Here, we simulated the environmental impacts from the conversion of grassland to corn and soybeans for 12 US Midwestern states using the EPIC (Environmental Policy Integrated Climate) model. Between 2008 and 2016, over 2 Mha of grassland were converted to crop production in these states, with much less cropland concomitantly abandoned or retired from production. The net grassland-cropland conversion increased annual soil erosion by 7.9%, nitrogen (N) loss by 3.7%, and soil organic carbon loss by 5.6% relative to that of existing cropland, despite an associated increase in cropland area of only 2.5%. Notably, the above estimates represent the scenario of converting unmanaged grassland to tilled corn and soybeans, and impacts varied depending upon crop type and tillage regime. Corn and soybeans are dominant biofuel feedstocks, yet the grassland conversion and subsequent environmental impacts simulated in this study are likely not attributable solely to biofuel-driven land use change since other factors also contribute to corn and soybean prices and land use decisions. Nevertheless, our results suggest grassland conversion in the Upper Midwest has resulted in substantial degradation of soil quality, with implications for air and water quality as well. Additional conservation measures are likely necessary to counterbalance the impacts, particularly in areas with high rates of grassland conversion (e.g. the Dakotas, southern Iowa).

Combined tillage with elements of Strip-till technology for maize in the Ciscaucasian zone

Relevance. The combined method of the main tillage, using certain methods of influence on the cultivated layer, forms a certain soil density. During the growing season of corn for grain, this indicator changes depending on the seasonal soil moisture and the intensity of the development of the root system of the plant, which is ultimately related to the yield of the crop. Material and method. The objects of research are two systems of basic tillage for corn for grain according to the predecessor winter wheat in the zone of unstable moisture of the Stavropol Territory using a dump and a combined method of basic tillage with elements of Strip-till technology. Soil: southern calcareous chernozem, slightly humus. The functional dependence of soil density on the supply of productive moisture and the intensity of development of the root system of grain corn was established by the method of the theory of dimensions. The method of fractal geometry was used to determine the degree of filling the soil space with root systems of grain corn under various systems of basic tillage.Results and Conclusions. It was found that the density of the soil is in direct functional dependence on the supply of productive moisture in the cultivated soil layer and the intensity of development of plant roots. The soil density during the seeding and flowering periods is higher by the Strip-till technology in comparison with the traditional one on average over the years by 0.02 g / cm3 and 0.03 g / cm3, respectively, and the moisture reserve in the spring period with Strip-till is 12 mm. The intensity of development of the root system according to the indicator D with the Strip-till system (1.58) by 0.31 units, more than with recommended processing (D = 1.27). The yield of corn for grain using the Strip-till technology is on average 0.22 t / g higher than with the recommended one, at a lower cost by 2395 rubles / ha.

Pre‐emergence herbicides, not carrier volume, impacted weed management in conventional tillage systems

AbstractThe use of pre‐emergence (PRE) herbicides is resurging as a standard practice for weed management in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] in the U.S. north‐central region. The increased use of PRE herbicides warrants investigation on the impact of spray carrier volume on weed control. Field experiments were established at Arlington, WI, in 2018 and 2019 and Janesville, WI, in 2018 to evaluate the influence of carrier volume on weed control of PRE herbicides in conventional tilled corn and soybean. Each experiment included three PRE herbicide premixes applied at crop planting at five carrier volumes (2.5, 5, 10, 15, and 17.5 gal acre−1). A nontreated control was also included in the experiment. Carrier volume did not influence weed control but PRE herbicide selection did. In corn, acetochlor + clopyralid + mesotrione and bicyclopyrone + mesotrione + S‐metolachlor provided 10–13% better annual grass, common ragweed (Ambrosia artemisiifolia L.), and giant ragweed (A. trifida L.) control than fluthiacet‐methyl + pyroxasulfone. In soybean, dimethenamid‐P + saflufenacil resulted in similar common ragweed control as the flumioxazin + pyroxasulfone treatment (79–85%), and 6 and 14% higher annual grass control and biomass reduction, respectively, compared to metribuzin + chlorimuron‐ethyl at Arlington. At Janesville, due to the high giant ragweed density in soybean, all herbicide treatments provided low levels of giant ragweed control (48–56%). Results from these field experiments suggest that lower carrier volumes could be used for PRE herbicide applications without compromising weed control in conventional tillage systems.

Soil Biological Response to Integration of Cover Crops and Nitrogen Rates in a Conservation Tillage Corn Production System

Core Ideas Use of N‐fertilizers decreased AMF populations and P, Ca, and Mg concentrations. Conservation tillage and cover crops increased C, N, and S cycling enzymes. Grass and brassica cover crops increased microbial populations compared to legumes. Agricultural production in the US Mid‐South has relied on frequent tillage and synthetic fertilizers decreasing soil health and system sustainability. Conservation tillage and cover crops can fill a vital role in reducing soil erosion while improving ecosystem functions. Seven cover crop blocks, including four legumes (berseem clover [Trifolium alexandrinum], crimson clover [Trifolium incarnatum L.], winter pea [Pisium sativum L.], and hairy vetch [Vicia villosa Roth], three grass & brassica (cereal rye [Secale cereale], forage radish [Raphanus sativus var. longipinnatus], and a cereal rye–forage radish mix), and one fallow control were established in northeast Louisiana to examine the influence of cover crop and urea fertilizer application rates (0, 235, 268, 302 kg N ha−1) on corn production and soil health under conservation tillage. Soil health indicators were measured each year following corn harvest and cover crop termination. The combination of cover crops and conservation tillage increased C and N enzyme activity over the 2 yr while arylsulfatase increased in the spring following cover crop termination only. Relative abundance of saprophytic fungi tended to be higher in legume plots compared to grass & brassica treatments. Overall, the application of N fertilizer at rates of 235 kg N ha−1 or higher decreased populations of AMF and concentrations of P, K, Ca, and Mg, but increased populations of Gram‐positive bacteria. The use of grass & brassica cover crops promoted K, S, Ca, and Mg availability, and supported greater abundance of total FAMEs and all FAME biomarkers except for saprophytic fungi.

Cropping System, Landscape Position, and Topsoil Depth Affect Soil Fertility and Nutrient Buffering

Core Ideas Depth to claypan, landscape position, and cropping system influence soil fertility and nutrient buffering. Accounting for landscape‐variable depth to claypan could improve P and K management. Cover crops can help increase soil organic matter content. Cover crops may help reduce P requirements on claypan soils. Precise nutrient management across claypan soil landscapes requires an understanding of how diversity in management practices impacts soil properties and nutrient buffering. Therefore, a study was performed at the Central Mississippi River Basin site of the USDA Long‐Term Agroecosystem Network from 2010 to 2016 to determine how depth to claypan (DTC), cropping system (CS), and landscape position (LP) affect soil properties, and whether accounting for these factors could improve fertility management. Treatments consisted of five CS {MTCS, mulch till corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]; NTCS, no‐till corn–soybean; NTCSW, no‐till corn–soybean–wheat (Triticum aestivum L.)–cover crop; CCRP, cool season conservation reserve program; and HAY, cool and warm‐season hay} and three LP (summit, backslope, and footslope), each with a distinct DTC. Soil test P (STP) was 9 kg P ha–1 greater on footslopes than summits. Soil test K (STK) and soil organic matter content (SOM) were greatest on backslopes and averaged 384 kg K ha–1 and 20 g kg–1, respectively, Soil test P was ≥49% and STK was ≥10% lower in NTCSW than in MTCS or NTCS. However, crop diversity in NTCSW maintained STP and increased SOM 2 g kg–1 over MTCS. Soil test P, pHs, and SOM were similar between CCRP and HAY, while STK in CCRP was greater at all LP. Lastly, deeper DTC caused greater P buffering and less K buffering than shallower DTC. These results indicate that eroded sideslopes with shallow DTC likely need more or more frequent P and less K than other LP.

Tillage Study for Corn and Soybeans: Comparing Vertical, Deep, and No-Tillage

The need for tillage in corn and soybean production in the Kansas River Valley continues to be debated. The soils of the Kansas River Valley are highly variable, with much of the soil sandy to silty loam in texture. These soils tend to be relatively low in organic matter (<2%) and susceptible to wind erosion. Although typically well drained, these soils can develop compaction layers under certain conditions. A tillage study was initiated in the fall of 2011 at the Kansas River Valley Experiment Field near Topeka to compare deep vs. shallow vs. no-till vs. deep tillage in alternate years. Corn and soybean crops are rotated annually. This is intended to be a long-term study to determine if soil characteristics and yields change in response to a history of each tillage system.

Long‐Term Impacts of Cropping Systems and Landscape Positions on Claypan‐Soil Grain Crop Production

Sustainable grain crop production on vulnerable claypan soils requires improved knowledge of long‐term impacts of conservation cropping systems (CS). Therefore, effects of CS and landscape positions (LP) on corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.) production were evaluated from 1991 to 2010 on a claypan soil in Missouri. Replicated treatments were three CS (2‐yr mulch till corn–soybean [MTCS], 2‐yr no‐till corn–soybean [NTCS], and 3‐yr no‐till corn–soybean–wheat–cover crop [NTCSW]) and three LP (summit, backslope, and footslope). Corn yield was equivalent among CS on the summit, 13% higher for NTCS and NTCSW on the backslope, and 14% lower for NTCSW on the footslope. Soybean yield was 8% higher on the summit, 24% higher on the backslope in NTCS and NTCSW, and 12% higher on the footslope in NTCSW than MTCS. Corn yield was more stable in NTCS and NTCSW than MTCS and increased in stability from the footslope to summit. Soybean yield was less stable in NTCS and NTCSW than MTCS and LP effects on stability were similar to corn. The coefficient of variation (CV) of corn yield across years was 10% points lower in NTCS and on the footslope, and of soybean yield was 10% points lower at the footslope and summit. Wheat production was not affected by LP. Results indicate that conservation systems often can maintain grain crop productivity equal to, increase yield stability above, and reduce yield variability below those of a conventional system on claypan soils.

Manure and Inorganic Nitrogen Affect Irrigated Corn Yields and Soil Properties

Manure can substitute for inorganic N fertilizers and can mitigate potential soil deterioration under irrigated corn (Zea mays L.) silage production, but the impact on yields, soil C and N have not been thoroughly studied in the semiarid western United States. Five N source treatments (dairy manure [DM, 412 kg N ha−1], DM + AgrotainPlus [DM+AP], SuperU [SU, 179 kg N ha−1], urea [179 kg N ha−1], and control [no N applied]) were studied (3 yr) to determine effects on silage and grain yields, N uptake, and changes in soil properties (soil organic carbon [SOC], total soil nitrogen [TSN], nitrate‐nitrogen [NO3–N], and soil test phosphorus [STP]) in an irrigated, conventionally‐ tilled clay loam soil under continuous corn silage production. Silage, grain, and stover yields and N uptake were greater with N application than control, with no difference between DM, DM+AP, urea, and SU. Fall soil NO3–N was greater with N application than control (0–90‐cm depth), but lower with DM than for SU (0–180‐cm depth). Soil test P was seven times greater with DM than with inorganic P after 3 yr. The SOC and TSN were strongly related to root and DM inputs, increasing with DM application but decreasing or remaining constant for SU, urea, and control treatments. Dairy manure is a valuable source of C, N, and P for irrigated tilled corn silage production with minimal NO3–N leaching or excessive soil P after 3 yr and can ameliorate residue removal and tillage impacts.

Vibration Test and Analysis of No-Tillage Planter on the Maize Stubble Surface

In order to improve metering accuracy of air suction type no tillage seeder in maize stubble ground operation, the vibration parameters of air suction seed metering device of the machine are tested and analyzed. Using the method of orthogonal experiment, with forward speed, ditching depth, ridge direction as the influence factors by experimental study on vibration characteristics.The results showed that in no tillage corn field conditions,Stubble height 10-30cm, ridge height is 0-8cm, the soil moisture content 19.78%, The soil temperature 12.7oC. Effects of sowing machine vibration frequency spectrum of 3.46-12.30Hz and 33.50-50.50Hz, the two band spectrum reflects the vibration characteristic of planter operation in the field, can be used as indoor and virtual test selection of reference data. The test results show that: the main factors causing vertical vibration of no tillage seeder metering device is 90o ridge direction, i.e. the surface roughness is greater, causing the vibration of no tillage planter seeding device more. The second is a seeding machine forward speed for 7km/h, i.e., no tillage planter work faster, causing vibration the greater. Finally is the sowing depth, the factors and agronomic seeds, soil fertility, soil humidity etc. Agronomic requirements are closely related, for the smaller vibration effect of no tillage seeder metering device.

Spatially Distributed Sheet, Rill, and Ephemeral Gully Erosion

AbstractEphemeral gully erosion seriously degrades agricultural soils, but few conservation planning tools adequately account for this form of erosion. To address this deficiency, this paper describes a spatially distributed adaptation of version 2 of the Revised Universal Soil Loss Equation and a new ephemeral gully erosion estimator. The modeled results were compared to runoff and sediment yield measured from 1975 to 1991 on a 6.3-ha instrumented watershed near Treynor, Iowa, managed with conventional tillage corn and containing a grassed waterway. Using a 3-m rectangular grid, this investigation determined surface drainage patterns and delineated concentrated flow channels where contributing areas exceeded 600 m2. Computed gully evolution based on soil properties, runoff, and sediment transport contributed approximately one-fourth of the total erosion, with the rest contributed by sheet and rill erosion. More than half of the eroded sediment was deposited within the grassed waterway. Without local cal...

Doses de glyphosate na dessecação de Urochloa ruziziensis antecedendo o plantio do milho

The Urochloa ruziziensis stands as a fodder alternative for the straw development in the tillage system. However, there are few information regarding to the management of desiccation, and the effect of the straw on the weed control. This study aimed at evaluating the efficacy of glyphosate into the management of desiccation of the U. ruziziensis, and the effect of the straw on the weed suppression in corn plantation. The experimental design was a randomized complete block with four replications. The treatments consisted of the following rates of glyphosate: 0; 360; 720; 1,440; 2,160 and 2,880 g ha-1, besides a testimony in fallow, and another in corn without straw. There was no influence of the U. ruziziensis straw in the development and the productivity of corn plants. The dose of 360 g ha-1 of glyphosate provided 100% of of U. ruziziensis desiccation at 28 days after its application, while the remaining straw (6.5 t ha-1) promoted 72.1% of reduction of the weeds population in the fallow portion at 30 days after the corn harvest. We concluded that the glyphosate doses evaluated were effective in the management of the U. ruziziensis desiccation, as well as, it can be an excellent alternative for the integrated management of the weeds in corn tillage system.

INFLUÊNCIA DA VELOCIDADE DE TRATOR E SEMEADORA DE PRECISÃO NA IMPLANTAÇÃO E PRODUTIVIDADE DA CULTURA DO MILHO VERDE - DOI: 10.13083/1414-3984.v22n01a03

O objetivo deste trabalho foi avaliar o desempenho de uma semeadora de precisão na implantação e caracteres produtivos da cultura do milho. Avaliou-se o desempenho da semeadora e produtividade da cultura. Foi utilizado um trator Massey Ferguson modelo MF 283 4x2 TDA e semeadora de precisão modelo SEED LINE. Foi regulado para distribuir 5,9 sementes. m-1 (65.000 plantas.ha-1), com 5 cm de profundidade e 90 cm entre linhas. O experimento foi montado em blocos casualizados, com três velocidades e quatro repetições, totalizando 12 unidades amostrais. As velocidades de operação foram 7,0; 5,5 e 4,5 km.h-1. Observou-se que a velocidade influenciou na velocidade periférica do disco dosador de sementes, número de sementes, espaçamento entre sementes, comprimento e largura da folha. Consequentemente, a maior velocidade periférica do disco dosador interferiu no número de sementes (3,9) e espaçamento entre sementes na maior velocidade. Para as condições experimentais recomenda-se a utilização da velocidade de trabalho de 4,5 km.h-1.