Strips Of Corn Research Articles

Design and Experiment of an Inter-Row Weeding Machine Applied in Soybean and Corn Strip Compound Planting (SCSCP)

To address the lack of specialized machinery for the mechanical weeding of SCSCP in the Huang Huai Hai region, this study designs a mechanized inter-row weeding machine for SCSCP. The machine features a reciprocating weeding shovel and an adaptive contouring mechanism for cultivation and soil loosening. This paper details the machine’s principles by analyzing the geometric relationship and mechanical model between the corresponding profiling quantities, which determine the relevant parameters for adaptive contouring to ensure stable operation on undulating ground. Furthermore, by optimizing the design of the weeding shovel’s reciprocating motion mechanism, combining EDEM simulation with the weeding shovel–soil interaction, it has been determined that, at various PTO shaft speeds, the optimal weeding efficacy is achieved with a blade-type weeding shovel structure when operating at a forward speed of 3.5 km/h. Field experiments were conducted with different PTO shaft speeds and weeding depths, using weeding and seedling injury rates as performance indicators. The results showed that, based on the optimal speed, the PTO shaft speed is 760 r/min, the operating depth is 3–5 cm, and the average row weeding rate is 90.4%. The average soybean and corn seedling injury rate is 3.4% and 4.2%, meeting the technical requirements for mechanical weeding.

Response of rhizosphere microbial community structure and production performance of corn and soybean to belt planting mode

Soybean and corn strip cropping takes full advantage of the root characteristics and plant height differences between soybean and corn, which can improve crop photosynthesis and nutrient uptake as well as capitalize on the marginal effect of corn. However, there is not enough in-depth research on the effects of soybean and corn strip cropping modes on inter-root microbial communities and crop yield traits and their correlations, and the functional genes of inter-root microbes. In this study, the structural composition and functional genes of soil inter-root microbial communities under different strip cropping patterns of soybean and maize, Mode 1, Mode 2, and Mode 3, were studied using macro-genome high-throughput sequencing, and the yield traits of soybean and maize were determined and the correlation was understood, taking Zhonglian Soybean 1505 and Tiyu 108 maize as test materials at the experimental base of the Research Institute of Agricultural and Livestock Sciences, Xing'anmeng, Inner Mongolia. correlation between the two. The following results were found. Redundancy analysis found that rhizosphere microorganisms are mainly bacteria, followed by viruses, followed by archaea, and fungi are the least. Relatively speaking, viruses and bacteria are more susceptible to the influence of planting patterns than fungi. Alpha diversity analysis shows that the diversity index changes significantly during the peak flowering period. There is no difference between the other two stages. The diversity of maize rhizosphere microorganisms under Mode 1 or Mode 2 modes is higher than that under Mode 3 modes, while the diversity of soybean rhizosphere microorganisms under Mode 3 modes is higher than the other two modes. Profiling analysis found that different growth periods and planting patterns lead to varying degrees of changes in community structure. The dominant bacterial phyla include Pseudomonas, Actinobacteria, Bacteroidetes, and Streptococcus. The dominant genera of bacteria are rhizobia, pseudomonas, erythrobacteria, and pseudomonas. The relative abundance of slow root rhizobia in the three growth stages of maize rhizosphere is relatively low. The results of yield traits showed that corn yield under Mode 1 and Mode 2 planting was significantly higher than that under pattern III; soybean yield under pattern III planting was significantly higher than that under the other two patterns, indicating that pattern I or II planting is suitable for corn production, while Mode 3 planting mode is more suitable for soybean production. Correlation analysis showed that S_Massilis_putida was significantly and positively correlated with maize yield, and S_lysobacter_capsici was highly significantly and significantly positively correlated with the number of soybean plants per square meter, and the number of plants in 2 square meters. This study contributes to our further understanding of the classification of inter-root microorganisms and their functional relationships in maize and soybean under different conditions.

Effectiveness of community-based initiatives for mitigation of land degradation after wildfires

Local communities, informed about the main post-fire environmental threats, applied land restoration techniques after the 2017 Ponte Caldelas wildfire (Galicia, Spain). Volunteers crews, supervised by local researchers/technicians identified high-severity burned areas and applied: post-fire mulch by using corn mulch (chopped corn at a rate of 4 Mg ha−1), corn strip mulch (chopped corn on 1-m wide contourline-strips at the bottom of plots, at 1 Mg ha−1) and wheat mulch (wheat straw, at 2 Mg ha−1), as well as acorn seeding with native oak (Quercus robur) acorns. Furthermore, the mulch effect on seed germination/root elongation was tested in the laboratory using direct topsoil samples and <0.45 microns-filtered soil solutions.Soil erosion during the first post-fire year was 27-11 Mg ha−1 for the Parada-Laforet sites, respectively. Corn, corn strip, and wheat mulching were very effective at reducing soil erosion, leading to 95, 76% and 93% less erosion than in untreated plots. During post-fire year 2 mulching was still effective at reducing soil erosion in the case of corn (87%) and corn strip mulch (73%), but less effective with straw mulch (36%). For the third year no differences were observed. Acorn seedling establishment failed in 96% of the cases. Still, survival rate of the germinated acorns was significantly higher on the mulched (50%) than on the untreated spots (26%; p<0.05). The laboratory experiments also showed higher germination rates, shoot length and biomass in mulched than untreated soils. The results demonstrated that the mulching measures applied by the local volunteers were effective for preventing soil erosion after forest fires. The success of ecosystem restoration with acorn seeding was low due to the low germination and the high predation by rodents, and further research is needed to scale acorn seeding to natural recruitment rates.

Grass Buffer Strips Improve Soil Health and Mitigate Greenhouse Gas Emissions in Center-Pivot Irrigated Cropping Systems

Declining water resources and soil degradation have significantly affected agricultural sustainability across the world. In the southern High Plains of USA, buffer strips of perennial grasses alternating with cultivated corn strips were introduced in center-pivot irrigated crop fields to increase agronomic production and ecosystem services. A study was conducted to evaluate soil carbon (C) and nitrogen (N) dynamics, greenhouse gas (GHG) emissions, and soil health benefits of integrating circular grass buffer strips in the center-pivot irrigated corn production system. Multiple parameters were assessed in the grass buffer strips, and at distances of 1.52, 4.57, and 9.14 m away from the edges of grass strips in corn strips. While grasses in the buffer strips depleted N compared to corn strips, potential C mineralization (PCM) was 52.5% to 99.9% more in grass strips than in corn strips. Soil microbial biomass C (MBC) content was 36.7% to 52.5% greater in grass strips than in corn strips. Grass buffer also reduced carbon dioxide (CO2) and nitrous oxide (N2O) emissions from corn strips. Grass buffer strips can improve soil health and sustainability in center-pivot irrigated cropping systems by increasing soil C components and reducing GHG emissions.

Assessing suitability of modified center pivot irrigation systems in corn production using low altitude aerial imaging techniques

This study evaluated corn (Zea mays var. indentata) canopy vigor and temperature variations using small unmanned aerial system (UAS) based spatiotemporal imagery data. The key objective was to develop understanding on site-specific suitability of the Mid Elevation Spray Application (MESA) and Low Elevation Spray Application (LESA) sprinkler systems in irrigating corn crop and potential water as well as energy savings. Aerial data was collected through small UAS flights at 100 m height above ground level and on 49, 59, 65, 77, 105, 114, 134 days after planting (DAP). Small UAS had 5-band multispectral and radiometric thermal imager on-board the platform. Custom image processing algorithms were developed to extract various vegetation indices (Normalized difference vegetation index [NDVI], Green NDVI [GNDVI] and Normalized difference red edge [NDRE]) and canopy temperature maps from the imagery data. Two sample T-test was performed on extracted data to understand significant difference, at 5% level, within the LESA and MESA treatments. For both the irrigation techniques, the crop vigor increased in the early growth stage (49, 65 DAP), peaked in the mid growth stage (77, 105, 114 DAP) and then decreased in the late growth stage (134 DAP). The MESA irrigated sections had higher vigor (NDVI, GNDVI, NDRE), but not significant, compared to LESA throughout the season. Similarly, the MESA irrigated areas had significantly (0.61–2.07 °C) cooler canopies than LESA. Such results were anticipated, in part due to the issues with the sprinkler heads used in LESA. The heads were being pulled off in the corn field, causing the weighted hose to damage the crop. A different kind of sprinkler head was used after this incident. However, some strips of corn had already been damaged. Overall, this study results confirm suitability of aerial imagery data in evaluating pertinent irrigation treatments. Additional season’s data would be needed to clearly understand which technique (LESA or MESA) is more suitable for irrigating corn crop in the central part of state of Washington.

Strip technology of corn and soy-bean cultivation for grain - a new stage in the development of soy-bean sowing on irrigated lands of the Volga region

Soy-bean plants develop more intensively and by the time of harvesting exceed the crops by means of the ordinary technology by 37-52 cm. Beans of the lower tiers are formed at an height of 18-20 cm (2-5 cm higher than in ordinary sowing), which is very important for mechanized harvesting, more beans with large seeds are formed. Ultimately, the grain yield with the new technology increases by 0.33-0.58 t/ha. Production tests of strip technology of soy-bean cultivation confirm its prospects in the conditions of irrigation of Zavolzhye. Especially it is perspective for the drought-resistant regions of a dry-steppe zone of the Volga region where during vegetation of crops air temperature rises till 35-40 degrees, but the relative humidity decreases to 12-8%. In these severe weather conditions existence of corn strips will reliably protect crops of soy-bean from hot winds and will be a reliable guarantor of increasing its harvest.

Pengembangan Mesin Penanam dan Pemupuk Jagung Terintegrasi dengan Pengolahan Tanah Alur

Pengembangan Mesin Penanam dan Pemupuk Jagung Terintegrasi dengan Pengolahan Tanah Alur

Investigation on application and performance of emission reduction measures at a pellet boiler

Various emission reduction measures may be used to reduce the emission of gaseous and particulate pollutants in the flue gas of small-scale firing systems. Further operation of obsolete firing systems and the reduction of pollutant emission during maloperation and part-load phases reveal the need of them. Beside their effect on pollutant concentrations, the adaption of them is a major research matter. Two emission reduction measures have been investigated at a multifuel pellet boiler: catalytic flue gas cleaning and electrostatic precipitation. Test stand studies have been carried out with pellets out of wood, miscanthus, and corn strip residue. The particulate matter concentration was reduced on average by 70–80 % for wood and miscanthus with the electrostatic precipitator and by 60 % for corn strip residue pellets. A dependency of the precipitation rate from particulate composition was observed. The investigations concerning the application and characterization of a catalyst demonstrate the conflict with respect to optimal process temperature for catalytic oxidation preventing blockage and thermal deactivation. Nevertheless, a carbon monoxide reduction of more than 50 % was observed. The investigations show that the reduction of carbon monoxide and particulate matter emissions from firing systems by retrofit emission reduction measures is possible. Still, further development is needed regarding an increase of particulate matter removal efficiency and a higher conversion rate for carbon monoxide and hydrocarbons.

A New Host Diagnosed with a Strain of Sugarcane mosaic virus in Florida: Red-Veined Prayer Plant (Maranta leuconeura erythroneura).

Prayer plants (Maranta spp.), which are indigenous to Brazil, are commercially produced in nurseries mainly to be sold as potted houseplants. However, in frost-free areas, they are also used as a ground cover. In March 2009, the Division of Plant Industry in Gainesville, FL received cuttings of red-veined prayer plant or red maranta (Maranta leuconeura erythroneura) from several nurseries in central Florida. The cuttings originated in Costa Rica. The presence of a viral infection was indicated by the mosaic pattern seen on the upper surface of the leaves and chlorotic lesions on the underside of leaves. Epidermal strips were taken and stained in Orange-Green (O-G) and Azure A (1). Microscopic examination revealed viral inclusions that stained only in O-G, indicating the presence of a potyvirus. Leaf dips were prepared for the electron microscope and flexuous rods consistent with a potyvirus were found. Indirect-ELISA using universal potyvirus antiserum (Agdia Inc., Elkhart, IN) confirmed the presence of a potyvirus infection. Total RNA was extracted from symptomatic tissue of five infected samples with Qiagen's RNeasy Plant Mini Kit (Qiagen Inc., Valencia, CA). Reverse transcription was conducted with the oligo d(T) primer M4T with AMV-RT at 37°C for 1 h. PCR was performed with primer M4 and a degenerate primer designed to amplify the 3' end of all potyviruses (2). A target amplicon of 1.7 kb was produced from all five samples. Three of these samples were cloned and sequenced. Approximately 1,250 bp were sequenced from each sample. The sequenced regions include the 3' end of the Nib gene, the complete coat protein, and the beginning of the 3' untranslated region (UTR). The nucleotide (nt) sequences were deposited into GenBank (Accession Nos. GQ853403-GQ853405). The nt sequences of the three samples were 97 to 98% identical to each other. When compared with other potyviruses in the GenBank, the samples showed closest nt identity, 92 to 93%, with several isolates of Sugarcane mosaic virus (AJ278405, AY836523, U57357, and U57356). Of the plant species mechanically inoculated (Chenopodium amaranticolor, C. quinoa, Datura stramonium, Gomphrena globosa, Nicotiana benthamiana, and Zea mays), only Z. mays (corn) showed symptoms (a mild mosaic). The same type of viral inclusions were seen in leaf strips of infected corn as in the Maranta. The corn plant reacted positively in direct-ELISA against antiserum to Sugarcane mosaic virus (Agdia Inc.). Cuttings of infected Maranta were observed in the greenhouse and indoor situations for several months. The plants infected with Sugarcane mosaic virus lacked vigor and most eventually died. ELISA tests done on a few surviving plants were positive for Sugarcane mosaic virus, but the results were inconsistent, indicating a possible low titer of virus in the plants as they were dying. To our knowledge, this is a new host for Sugarcane mosaic virus, but it does not appear that Maranta will become a significant new reservoir of this virus for sugarcane or corn growers. However, infected cuttings can greatly decrease the production of this plant as an ornamental.

Development and Performance Assessment of a Grain Combine Feeder House-Based Mass Flow Sensing Device

Yield monitors have become an indispensable part of many precision agriculture systems because of their ability to quickly and efficiently measure yield variability within a field. The current technology of measuring grain yields with sensors mounted in the clean grain elevator is error prone due to mass flow variations caused by the threshing and separating operations. To reduce the effect of combine dynamic errors, a new crop mass flow sensing technology is being developed. This new sensor measures the tension on the feed conveyor drive chain, as it is believed that the tension on this chain is related to the flow of biomass through the feeder housing. The initial field tests were conducted in 160 m strips of corn that were broken into six blocks of varying grain yields. An analysis of the data indicated that chain tension sensors are sensitive to differences between the blocks of varying grain yields. Additional tests, under normal field conditions, were also conducted under varying biomass volumes controlled by selecting one of three specific stripper plate settings on the combine corn head. The chain tension sensor could detect differences between the stripper plate settings, as the greatest chain tensions were recorded at the narrowest stripper plate width. Results from both field trials were compared to yield data collected from an impact-style mass flow sensor located in the clean grain elevator. The results indicated that biomass flow sensing at the feeder housing might complement existing technologies to improve yield monitor data quality.

ارزیابی جذب و کارایی مصرف نور توسط کانوپی کشت مخلوط ذرت و لوبیا

سیستمهای کشت مخلوط یکی از روشهای مدیریت صحیح تولید محصولات زراعی است که منجر به بهبود جذب و کارایی مصرف منابع توسط گیاهان می شود. با همین هدف به منظور ارزیابی اثرات کشت مخلوط نواری بر میزان جذب و کارایی مصرف نور ذرت و لوبیا آزمایشی در سال 1388 در مزرعة تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد در غالب طرح بلوکهای کامل تصادفی با 3 تکرار و 6 تیمار اجرا شد. تیمارهای آزمایشی شامل کشت خالص ذرت، کشت خالص لوبیا، عرض نوار 2، 3، 4 و 5 ردیف کاشت ذرت و لوبیا بود. آزمایش در یک سیستم کم نهاده اجرا شد و از مصرف هر گونه مواد شیمیایی (کودهای شیمیایی و آفت کش‌ها) خود داری شد. هرکرت آزمایشی به ابعاد 4 متر طول در 5/7 متر عرض بود که تیمارهای مورد آزمایش، به صورت جایگزینی در آنها اعمال شد. نتایج آزمایش نشان داد که شاخص سطح برگ، میزان جذب نور، تجمع مادة خشک و کارایی مصرف نور ذرت و لوبیا در تمام تیمارهای کشت مخلوط نسبت به تک کشتی افزایش پیدا کرد. افزایش عرض نوار در تیمارهای کشت مخلوط نسبت به تیمار عرض نوار 2 ردیفی، به استثنای کارایی مصرف نور (3/8 و 5/14 درصد) منجر به کاهش شاخص سطح برگ (2/34 و 5/5 درصد)، میزان جذب نور (5/20 و 2/11 درصد) و تجمع مادة خشک (1/13 و 5/1 درصد) به ترتیب در ذرت و لوبیا شد. با افزایش عرض نوار مقادیر صفات نام برده در ردیف‌های مرکزی نسبت به ردیف‌های حاشیه ای کاهش بیشتری یافت. اثرات تسهیل و تکمیل کنندگی کشت مخلوط بر صفات مورد بررسی هم در ردیف‌های حاشیه ای و هم در ردیفهای مرکزی برای ذرت بیشتر از لوبیا بود. میانگین کارایی مصرف نور ذرت و لوبیا در طول فصل رشد به ترتیب از 65/1 و 98/0 در تیمار کشت خالص تا 94/1 و 15/1 گرم بر مگاژول تشعشع فعال فتوسنتزی در تیمار عرض نوار 2 ردیفی، متغیر بود.

Response of Corn to Banded Zinc Sulfate Fertilizer in Fields with Variable Soil pH

There are soil series that contain free calcium carbonate (CaCO3) within fields where the surrounding pHs of the soil series are slightly acid. The objective was to study corn (Zea mays L.) grain yield response to zinc (Zn) fertilizer on different soil series within fields. The study was conducted at 12 sites between 1998 and 2000. Treatments were 0 and 5.6 kg Zn ha−1 applied in bands to field‐length strips of corn and replicated four times. Multiple soil series were identified at each site, and treatment pairs were located within them. Grain yields, whole plant (V6 to V10 growth stage), and grain Zn content and uptake were measured. The most common result was no response to Zn application. However, significant yield decreases occurred on some soils as a result of Zn application in two situations: on soils with high soil‐test Zn or on soils with low soil‐test Zn and high pH.

Microenvironment of a corn–soybean–oat strip intercrop system

The microenvironment of a corn ( Zea mays L.)–soybean ( Glycine max [L.] Merr.)–oat ( Avena sativa L.) narrow strip intercrop system was studied on four farms in Iowa, USA during 1991–1993 (one or two farms studied each year) with the objective of explaining previously observed patterns of strip-crop yields. Air and soil temperatures, humidity, wind, and photosynthetic photon flux density (PPFD) for each row in a strip were recorded continuously during 4–13-day periods several times during each growing season; short-term measurements of light extinction through the corn and soybean canopies were made late in the 1993 growing season. Soybean biomass in September 1993 was also determined. Early in the growing season, there typically were no significant differences among rows within a strip in any environmental or growth variable. Later in the growing season, daily PPFD received varied more across each strip than any other environmental variable measured; the outer side of edge rows of corn in north–south rows typically received significantly higher daily PPFD (2–38% more) than inner rows in the strip, while the outside of the soybean row furthest from corn received 36–140% greater PPFD than the corn-side of the row next to the corn strip. Soybean height; leaf mass per leaf area; and leaf mass, stem mass, and pod mass per unit land area in September were strongly related to daily PPFD, with all except height increasing with greater PPFD. Total biomass increased by 32% from the row closest to corn to the row furthest from corn, although there was no change in the ratio of leaf:stem:pod with row position. Thus, PPFD varied the most across the strips of any environmental variable, and crop growth was closely related to PPFD received.

Predicting western corn rootworm (Coleoptera: Chrysomelidae) larval injury to rotated corn with Pherocon AM traps in soybeans.

Crop rotation for portions of east central Illinois and northern Indiana no longer adequately protects corn (Zea mays L.) roots from western corn rootworm, Diabrotica virgifera virgifera LeConte. Seventeen growers in east central Illinois monitored western corn rootworm adults in soybean (Glycine max L.) fields with unbaited Pherocon AM traps during 1996 and 1997. In the following years (1997 and 1998), growers left untreated strips (no insecticide applied) when these fields were planted with corn. Damage to rotated corn by rootworms was more severe in untreated than in treated strips of rotated corn, ranging from minor root scarring to a full node of roots pruned. Densities of western corn rootworms in soybean fields from 1996 were significantly correlated with root injury to rotated corn the following season. Adult densities from 1997 were not significantly correlated with root injury in 1998, due to heavy precipitation throughout the spring of 1998 and extensive larval mortality. Twenty-eight additional growers volunteered in 1998 to monitor rootworm adults in soybean fields with Pherocon AM traps based on recommendations that resulted from our research efforts in 1996 and 1997. In 1999, these 28 fields were rotated to corn, and rootworm larval injury was measured in untreated strips. Based on 1996-1997 and 1998-1999 data, a regression analysis revealed that 27% of the variation in root injury to rotated corn could be explained by adult density in soybeans the previous season. We propose a sampling plan for soybean fields and a threshold for predicting western corn rootworm larval injury to rotated corn.

Influence of Corn Phenology on Adult Western Corn Rootworm (Coleoptera: Chrysomelidae) Distribution

Abstract Field studies were designed to more clearly determine how adult western corn rootworm, Diabrotica virgifera virgifera LeConte, population distribution patterns are altered over time by changes and contrasts in corn (Zea mays L.) plant phenology using whole-plant beetle counts as the sampling tool. In 1994, studies were conducted in a model system consisting of a late-planted corn strip placed in the middle of an early-planted cornfield. The system was replicated over three fields. Large-scale variation was modeled using trend-surface regression analysis to describe the relationship between beetle counts and distance from the center of the late-planted strip. In each field, the beetle distribution became greatly skewed toward the late-planted strip when the strip was either in the tassel or silk stage and the surrounding field was ≥ blister stage. In 1995, studies were conducted in and at the interface of two adjacent cornfields that were planted 9 d apart. Count data were analyzed to quantify pop...

Strip Intercropping Effects on Yield and Yield Components of Corn, Grain Sorghum, and Soybean

Strip intercropping of corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench] and soybean may be a viable alternative to monoculture cropping to help reduce soil erosion. Careful study of yields and yield components can add to understanding crop performance and contribute to design of more productive systems. Rainfed and irrigated experiments were conducted in eastern Nebraska from 1988 to 1990, on a Sharpsburg silty clay loam (fine, smectitic, mesic Typic Argiudoll), to quantify strip‐intercropping effects on crop yields and yield components. Corn border‐row and grain sorghum border‐row yields next to soybean increased significantly compared with inside rows in the strips. Increased seed number and seed weight contributed to higher corn border‐row yields, while only seed number increased in grain sorghum border rows. Soybean border‐row yields were lower next to all corn strips and next to grain sorghum strips at the rainfed site. Soybean seed number was lower in border rows next to corn. Corn border‐row increases in seed number and seed weight indicate that competition for resources was important in both reproductive and grain‐filling periods; sorghum border‐row increases in seed number suggest competition only in the reproductive period. Higher corn density in border rows may further exploit a competitive advantage with soybean in the reproductive period, perhaps increasing system productivity. Whole‐system productivity of strip‐intercropping systems was a maximum of 4% higher than monocultures of component crops, and gross returns did not differ between the two systems. If there is need to control soil erosion, strip intercropping can be equally profitable to monoculture if production costs are similar.

Movement of Corn Rootworm Larvae (Coleoptera: Chrysomelidae) Between Border Rows of Soybean and Corn in a Strip Intercropping System

Strip intercropping of corn may provide spatial and temporal diversity for management of extended-diapause corn rootworm populations. Strip-intercropped corn may sustain infestations of corn rootworm larvae attributable to migration of larvae into 1st-yr corn from soil previously planted to corn. Row-specific distribution of corn rootworm eggs and adult emergence were determined in a strip intercropped system, and effects of interstrip cultural and insecticidal treatments on rootworm infestation of outer rows were evaluated. Corn rootworm eggs were found in all rows of strips previously planted to corn. Root injury ratings were significantly higher in the outer rows than in the interior rows of corn adjacent to the previous year’s corn strips. Oilseed meal and insecticide treatments were associated with lower corn rootworm adult emergence and larval root injury than was found in untreated plots. Higher rootworm adult emergence and root injury scores in tillage treatments, where the soil was disturbed by ripping with a cultivator shank, were attributed to increased soil pore space that facilitated larval movement into adjacent corn strips. Fewer adults emerged and less root injury occurred in outer rows of corn adjacent to soybean strips that were subjected to interrow soil compaction from wheel traffic. In severely infested fields, deliberate compaction of interrow soil or incorporation of cruciferous plant material into soil between strips are possible noninsecticidal management options for reducing severe corn rootworm infestation of outside rows of corn in strip intercropping systems.

Fertilizer and Soil Nitrogen Use by Corn and Border Crops in a Strip Intercropping System

AbstractCorn (Zea mays L.) has greater yield potential when strip‐intercropped than when monocropped, but this potential may be compromised by a failure to understand how N requirements change with row position and the possible N competition of adjacent crops. A four block, completely randomized, split‐plot experiment was conducted on a Haig loam soil (fine, smectitic, mesic Vertic Argiaquolls) in southern Iowa, to determine crop utilization of N fertilizer pointinjected into corn rows. Nitrogen fertilizer uptake was evaluated in (i) corn rows injected with labeled N fertilizer; (ii) corn rows adjacent to the injected rows; and (iii) plants at the edge of the adjacent soybean [Glycine max (L.) Merr.] and oat (Avena sativa L.)‐alfalfa (Medicago saliva L.) strips. Main treatments consisted of three tillage systems: conventional tillage (CT), reduced tillage (RT), and no‐till (NT). Subplot treatments consisted of point injection of l5N‐enriched NH4NO3 (67 kg N ha−1) in‐row at three row positions within the corn strips. Grain and stover yield, Kjeldahl N, and isotope composition of plant materials were determined. Corn yield and labeled‐N recovery differed with tillage to the extent that tillage affected early and total season moisture availability. Labeled‐N recovery in labeled rows did not differ with row position. Labeled‐N recovery in unlabeled rows or crop borders was typically less than 5% of that recovered by labeled rows. Nitrogen is primarily recovered by the row to which it is applied; therefore, row‐by‐row precision applications seem to be an appropriate management tool.

Increased Soil Enzyme Activities under Two Row Crops

AbstractThis study examined the influence of crop on the spatial pattern of soil enzyme activities in a Rego Humic Gleysol (Aquoll) strip‐cropped to corn (Zea mays L.) and soybean [Glycine max (L.) Merr.]. Soil samples (0–23‐cm depth) were collected at 20‐cm spacings along transects across adjacent plant rows. Activities of dehydrogenase, urease, glutaminase, phosphatase, arylsulfatase, and β‐glucosidase were compared for soil samples collected from within vs. between crop rows. Spectral analysis was used to test for a cyclical pattern of soil enzyme activities along transects. The spatial pattern of all six soil enzyme activities was sometimes influenced by the crop. Greater enzyme activity in the row than in the furrow was observed in approximately one‐third of the cases examined. In approximately two‐thirds of the cases where the class comparison indicated greater enzyme activity in the row than in the furrow, enzyme activity appeared to cycle at a period equal to the row spacing. Periodograms also indicated cycling at other periods, and there was considerable random variation in enzyme activities along the transects. Dehydrogenase and β‐glucosidase activities differed between strips of corn and soybean on some sampling dates. The spatial pattern of soil enzyme activities indicated that they behaved similarly as general indices of microbial activity at the scale of measurement. Comparisons of soil enzyme activities between sites within the growing season should account for influence of the crop.

Strip Intercropping Corn and Alfalfa

Strip intercropping annual row crops can improve productivity, but the effect of strip cropping grain and perennial forage crops has not been thoroughly investigated. This study was conducted to evaluate the productivity and profitability of strip intercropping corn (Zea mays L.) and alfalfa (Medicago sativa L.). Alternating strips of corn and alfalfa of three widths (10, 20, and 40 ft) were compared in a field trial conducted from 1988 through 1990. Corn silking dates, heights, grain yields, and moisture were determined for each row within strips. Alfalfa yields and forage quality were determined for harvest strips within plots and for whole plots. Land equivalent ratios (LER) and gross returns to both strips and sole crops were calculated. In the drought of 1988, neither corn nor alfalfa yields differed due to strip width or from the sole crop yield. In 1989, corn yields were lowest for the sole crop (146 bu/acre), increased 3% in 40-ft strips, and 10% in 10- and 20-ft strips. In 1990, corn yields were also lowest for the sole crop (123 bu/acre), and increased 6% in 40-, 11% in 20-, and 17% in loft wide strips. Alfalfa yields did not differ due to strip width or from the sole crop yield in 1989. In 1990, alfalfa yields in strips vs. the sole crop were reduced 10% only for the 10-ft wide plots. Land equivalent ratios were lowest in 1988, with values below 1.00 for 10- and 40-ft strips. All strip widths had values above 1.00 in subsequent years. Maximum LERs were 1.02, 1.08, and 1.06 for 20-ft strips in 1988, 1989, and 1990, respectively. In all years, 20-ft wide strips had the greatest economic advantage, returning $6, $29, and $17/acre over sole crops in 1988, 1989, and 1990, respectively. Increases in prices received for crops always increased the advantage of strip intercropping.