Soil Tillage Systems Research Articles

Soil CO2 emission and short-term soil pore class distribution after tillage operations

Alongside the agricultural development in Brazil, concerns have arisen about its environmental impacts, such as the emissions of CO2 resulting from soil cultivation and management practices in agricultural production systems. The aim of this study was to investigate the temporal variation in CO2 emissions and soil physical attributes in response to the process of soil particle rearrangement after soil tillage operations. The study was conducted in three adjacent areas of 10 × 3 m, subjected to two soil tillage systems: (i) rotary hoe + conventional leveling harrow, representing an intensive soil tillage (IT); (ii) disc harrow + leveling harrow, characterizing a reduced tillage (RT). The soil of the third area was not tilled, representing the no-tillage (NT) system. Daily measurements of soil CO2 emission (FCO2), soil temperature, soil moisture, pore class distribution, bulk density, penetration resistance, water-free pore space, weighted mean diameter, aggregate stability index, total organic carbon, and particulate organic carbon were performed during a period of 29 days after soil tillage. On the first day after tillage, FCO2 was 87% higher in the plot under IT (3.86 μmol m−2 s−1) than RT (2.06 μmol m−2 s−1) and 147% higher than in the plot under NT (1.56 μmol m−2 s−1). The variations in soil density and penetration resistance declined as of the 12th day after tillage. This effect was considered a natural process of soil consolidation and influenced the temporal variation of soil CO2 emissions. Pore class distribution is an essential physical attribute to explain the temporal variations of soil CO2 emissions, and these classes are influenced by the applied management. Therefore, the study of these attributes must be taken into account when assessing the variation of CO2 emissions from agricultural soils.

Soil load support capacity increases with time without soil mobilization as a result of age-hardening phenomenon

Soil compaction is a result of soil compression, and this effect depends on the pressure applied and the soil structure. Nevertheless, studies regarding the effects of long-term tillage systems on strengthening of particle bonds are scarce. Thus, we aimed to study the soil bond strengthening due to the age-hardening phenomenon using the soil load support capacity model of an Oxisol managed under different tillage systems in Southern Brazil. Soil samples were collected from three soil layers (0.0–0.10 m; 0.10–0.20 m and 0.20–0.30 m) and five soil tillage systems of conventional tillage; minimum tillage with chiselling performed every year or every three years; and no-tillage for 11 or 24 years. Age-hardening was investigated using the soil load support capacity model. Soil cores were equilibrated at four matric potentials (−6, −33, −100 and −500 kPa) and submitted to uniaxial compression tests to obtain preconsolidation pressure. The soil load support capacity models were affected by the tillage systems. The long-term no-tillage presented the highest soil load support capacity for the same bulk density and water content in all layers, demonstrating greater resistance to additional compaction. Higher preconsolidation pressure values in long-term no-tillage at the same soil bulk density and water content were attributed to the age-hardening phenomena, which increased the number and strength of bonds among soil particles, leading to higher soil cohesion. Longer time under no-tillage improves the soil structure and soil load support capacity. Thus, soil mobilization strongly affected the soil structure by breaking particle bonds leading to the greater compaction.

TECHNOLOGICAL GRAIN QUALITIES OF SPRING COMMON WHEAT DEPENDING ON THE SYSTEM OF SOIL TILLAGE

The work presents the results of the research into studying technological qualities of the grain of spring common wheat, variety Siberian Alliance, depending on the soil tillage system in grain-fallow crop rotation. The research was conducted in the northern forest-steppe of Kuznetsk Depression in the experimental plot established in 1974, in a fourcourse grain-fallow crop rotation (fallow – wheat – peas – pure barley and barley intercropped with melilot). Various soil tillage systems were applied: deep moldboard, deep combined, minimum combined, minimum moldboard. The study of grain quality took place on crops of spring common wheat by three preceding crops on bare fallow and greenmanured fallow with rape and melilot. The soil of the experimental plot was characterized as leached chernozem, medium-textured, medium humus, heavy-loam. The humus content in an arable layer was 8.2%. Crops of spring common wheat were sown with all types of soil tillage systems by the multifunction tillage and sowing machine Tom’5.1. Optimum conditions for obtaining grain of spring common wheat of high quality were formed on green-manured fallow with intercropping of melilot and rape by moldboard and minimum combined soil tillage. On average, the mass of 1000 grains amounted to 37.0-37.4 g, in 2017 – 41.0 g, natural weight – 725-751 g/l, hardness – 80-81%, content of crude gluten – 32-33%, mass fraction of protein – 15.2-15.3%. Positive correlations between indices of grain quality, r = 0,40700,6594 were established. According to the State Standard Specification P 52554-2006, cultivar of common spring wheat Siberian Alliance confirms its belonging to the strong wheat type by the quality indices obtained.

Енергозберігаюча система обробітку грунту на базі електрифікованого мотоблоку

Small-sized mobile aggregates in the form of motoblocks with internal combustion engines with the capacity of 1-7 kW domestic and foreign production were widely used to increase the efficiency of production of vegetables in protected ground soils. During the work of mobile units with internal combustion engines in greenhouses and greenhouses, noise and gas pollution increase, which negatively affects not only people but also plants. More promising for work in protected soil structures are mobile aggregates with traction electric motors, which are called electric motors, as ecologically clean aggregates that do not have the named drawbacks. The purpose of the research is to substantiate and elaborate the structural and electromechanical scheme of an energy-saving soil cultivation system based on an electrified motor block, to obtain a balance of capacities, and to create a mode of control of the DC motor by successive excitation along the maximum of efficiency in the main sections of its mechanical characteristics. The electric power unit receives power with a flexible cable, which is supplied with electricity from the AC network. The gate converter converts the electric energy of an alternating current into the electric power of a direct current necessary for further electromechanical transformation in a traction electric motor. The structural and electromechanical schemes of the energy-saving soil tillage system based on the electrified motor block are substantiated. The obtained control characteristics provide the control of the DPS at the maximum efficiency and the set value of the load factor. In a relatively large zone, the change in the load factor of the engine efficiency is close to the maximum value with a loading coefficient of 0.7-0.9. This significantly simplifies the practical implementation of the modes of control of the DPS with the use of simple design of the gate transducers in the form of thyristor voltage regulators.

Soil Physical Quality in Sugarcane Field Under Cover Crop and Different Soil Tillage Systems

Currently, the management practices employed in Brazilian sugarcane plantations have contribute to soil physical degradation and, few studies considering the effect of cover crop associated with conservationist soil tillage systems to control or even reverse this process. Therefore, with the aim to assess the impact of cover crop and tillage systems on the least limiting water range (LLWR) and the S index in two soils of different textures used for sugarcane production, a fieldwork was carried out in two sugarcane plantations in the state of São Paulo, Brazil. The experimental design is a split-plot with four repetitions. The main factor consisted of soil cover vegetation: cover crop and fallow, and the second factor, the tillage system: minimum tillage and conventional tillage. The data of this study demonstrated that clayey and medium-textured soil are sensitive to the management systems used. The use of cover crop promoted an increase of LLWR (average incremental rate of 105% for clayey and 100% for medium-textured soil) and S index (average incremental rate of 16% for clayey and 10% for medium-textured soil). The maintenance of soil under fallow represented restrictive conditions for the growth/development of the plants due to the degradation of the soil structure. In addition, conservation management systems, such as minimum tillage, resulted in better soil physical quality when associated with cover crop. Finally, the clayey and medium-textured soil, show good S index during the first cycle of sugarcane cultivation.

Soil wet aggregate distribution and pore size distribution under different tillage systems after 16 years in the Loess Plateau of China

In the Loess Plateau of China, conventional tillage is defined as the tillage without crop residues left on the soil surface and ploughed twice a year. The use of alternative practices is a way to reduce soil erosion. Our objectives were to assess the long-term impacts of different soil tillage systems on soil physical and hydraulic characteristics, emphasizing management practices to improve the soil physical qualities (reduce bulk density and increase stability of aggregate) under the conservation tillage system in the Loess Plateau of China. Conventional tillage (CT), no tillage (NT), and sub-soiling (SS) were applied in this experiment. Soil wet aggregates distribution and stability, soil organic carbon (SOC) content, soil water retention curves and pore size distributions were measured. The results showed that in the 0–10 cm and 10–20 cm depth soil layers, NT and SS treatments showed a significantly higher proportion of wet aggregates >250 μm (macroaggregates) compared to CT. In these two layers, the proportion of wet aggregates <53 μm (microaggregates) was significantly higher in CT with respect to NT and SS. SOC content increased as the aggregate fraction size increased, and was higher within wet aggregates >250 μm than within the 250–53 μm and < 53 μm (silt + clay) fractions at both depths. In addition, the conservation tillage (NT and SS) can result in improved total porosity and reduced soil bulk density compared with CT in the surface layer. Pore size distribution in CT soil was unimodal, with the maximum in the 10–30 μm matrix pores of the surface layer. However, in the surface layer the pore size distributions from NT and SS showed a dual porosity curve, with two peaks in the matrix and structural pore areas. The 10–20 cm layer showed similar pore size distributions in each treatment. After scanning the soils by micro-computed tomography, we visualized the pore characteristics. The images showed that CT reduced the long and connected macropores compared with conservation tillage. Overall, soil aggregate stability and soil macropores are most improved under conservation tillage. Conservation tillage with crop residues should be adopted instead of conventional tillage, as an effort to improve crop yield and control soil erosion in the Loess Plateau of China.

New challenges in soil management

Soil management represents two important tasks that are harmonization of the soil protection with demands of the crop to be grown on the given land under prevailing farming condition. Further goals are to preserve and/or develop the soil physical, biological and chemical condition and to avoid the unfavourable changes of the soil biological activity and the soil structure. Classical authors emphasised the importance of creating proper seedbed for plants. In the physical approach, tillage was believed to play an important role in controlling soil processes. Consequently, the period of several centuries dominated by this approach is referred to as the era of crop-oriented tillage (Birkás et al., 2017). The overestimation of the importance of crop requirements resulted in damaging the soils, which inevitably led to turn to the soil-focused tillage. Since the first years of climate change, as the new trends have raised concern, tillage must be turned into a climate-focused effort with the aim of reducing climate-induced stresses through improving soil quality.&#x0D; The development of soil management has always been determined by the economical background. At the same time, deteriorating site conditions have contributed to the conception of new tillage trends by forcing producers to find new solutions (e.g. dry farming theory in the past or adaptable tillage theory nowadays). Győrffy (2009) recited the most important keywords were listed in 2001 and that seemed to be important in the future of crop production. These keywords (endeavours) were as follows:&#x0D; − Biofarming, organic farming, alternative farming, biodynamic farming, low input sustainable agriculture;&#x0D; − Mid-tech farming, sustainable agriculture, soil conservation farming, no till farming, environmentally sound, environmentally friendly, diversity farming;&#x0D; − Crop production system, integrated pest management, integrated farming, high-tech farming;&#x0D; − Site specific production, site-specific technology, spatial variable technology, satellite farming;&#x0D; − Precision farming.&#x0D; Győrffy’s prognosis proved to be realistic and the efforts mentioned above have mostly been implemented. New challenges have also appeared in soil management in relation to the last decades. The most important endeavours for the future are:&#x0D; 1) Preserving climate-induced stresses endangering soils.&#x0D; 2) Turn to use climate mitigation soil tillage and crop production systems.&#x0D; 3) Applying soil management methods are adaptable to the different soil moisture content (over dried or wet may be quite common).&#x0D; 4) Use effectual water conservation tillage.&#x0D; 5) Use soil condition specific tillage depth and method.&#x0D; 6) Adapting the water and soil conservation methods in irrigation.&#x0D; 7) Preserving and improving soil organic matter content by tillage and crop production systems.&#x0D; 8) Considering that stubble residues are matter for soil protection, humus source and earthworm’ feed.&#x0D; 9) Site-specific adoption of green manure and cover crops.&#x0D; 10) Applying site-adopted (precision) fertilization and crop protection. Considering the development in agriculture, new endeavours will occur before long.

Changes in weed seed bank and flora as affected by soil tillage systems

Changes in weed seed bank and flora as affected by soil tillage systems

Tillage effects on the soil water balance and the use of water by oats and wheat in a Mediterranean climate

In the drylands of the Cordillera de la costa of central Chile, the water balance variables are governed by a typical Mediterranean precipitation pattern. In this environment, agronomic management practices are mainly aimed at improving the availability of water in the soil, creating optimal conditions for the crops to effectively use the available water. The aim of this study was to determine the soil water balance and water use efficiency in an oat-wheat crop rotation grown in a duplex soil with two contrasting textural layers. An experiment was conducted during the years 2007–2009 at the Experimental Center Cauquenes located in the inner dryland of the coastal range of central Chile. Conventional tillage (Ct), no tillage (Nt) and no tillage with subsoiling (Nt + Sb) systems were established. The water balance for each year of study and the total biomass, grain yield, harvest index (HI), 13C discrimination (Δ13C), crop evapotranspiration (ETc) and water use efficiency (WUE) were determined. The crop evapotranspiration (ETc) varied between 273 and 360 mm, with an overall seasonal average of 300 mm. The conservation tillage systems have a positive effect on SWC; however, the results are related to the annual rainfall. In a dry year, Nt + Sb improved the water use efficiency to 8.10 kg ha−1 mm−1, higher than that of Ct and Nt by 40% and 55%, respectively. We have demonstrated how understanding the impact of soil tillage systems on compacted soils with an abrupt contrasting soil texture can improve water use efficiency and consequently reduce water loss.

Plant Population and Maize Grain Yield: A Global Systematic Review of Rainfed Trials

Maize (Zea mays L.) productivity has increased globally as a result of improved genetics and agronomic practices. Plant population and row spacing are two key agronomic factors known to have a strong influence on maize grain yield. A systematic review was conducted to investigate the effects of plant population on maize grain yield, differentiating between rainfall regions, N input, and soil tillage system (conventional tillage [CT] and no‐tillage [NT]). Data were extracted from 64 peer‐reviewed articles reporting on rainfed field trials, representing 13 countries and 127 trial locations. In arid environments, maize grain yield was low (mean maize grain yield = 2448 kg ha−1) across all plant populations with no clear response to plant population. Variation in maize grain yield was high in semiarid environments where the polynomial regression (p &lt; 0.001, n = 951) had a maximum point at ∼140,000 plants ha−1, which reflected a maize grain yield of 9000 kg ha−1. In subhumid environments, maize grain yield had a positive response to plant population (p &lt; 0.001). Maize grain yield increased for both CT and NT systems as plant population increased. In high‐N‐input (r2 = 0.19, p &lt; 0.001, n = 2 018) production systems, the response of plant population to applied N was weaker than in medium‐N‐input (r2 = 0.49, p &lt; 0.001, n = 680) systems. There exists a need for more metadata to be analyzed to provide improved recommendations for optimizing plant populations across different climatic conditions and rainfed maize production systems. Overall, the importance of optimizing plant population to local environmental conditions and farming systems is illustrated.

Research Concerning the Influence of Soil Tillage Systems on Weeds Control and Corn Hybrids Yield Cultivated in Southeastern Romania

Abstract The paper presents the yield results obtained in 2017 for the corn crop grown in the soil and climate conditions of Southern Romania (Calarasi county). The purpose of the research was to analyze the behavior and yield of a range of corn hybrids from different FAO groups: DKC 4590 (FAO 350), PP9911 (FAO 410) and Olt (FAO 430) under different soil tillage systems. The conventional tillage system applied was plowing at 20 and 30 cm, while scarifying at 30 and 40 cm and Tiger 3 MT at 20 and 30 cm were used for the minimum tillage system. The average yield of the three hybrids analyzed was 8,130.3 kg/ha in the conventional tillage system (plowing at 20 and 30 cm) with mechanical weeding, while for the conventional tillage system without mechanical weeding the yield was 7,682.2 kg/ha. The minimum tillage variants (scarifying and Tiger 3 MT) recorded an average yield of 6,746.4 kg/ha when mechanical weeding was applied and 6,474.9 kg/ha for the variants without mechanical weeding. Regarding the degree of weeding by tillage system, in the conventional tillage system (plowing at 20 and 30 cm) with mechanical weeding the number of weeds was 4.2 plants/m2 and 9.3 plants/m2 for the variants without mechanical weeding. The minimum tillage variants (scarifying and Tiger 3 MT) recorded 12.8 weeds/m2 when mechanical weeding was applied and 16.2 weeds/m2 for the variants without mechanical weeding.

GROWTH, DEVELOPMENT AND PRODUCTIVITY OF WINTER WHEAT DEPENDING ON THE SOIL TILLAGE AND SOWING SYSTEMS

The results of the field experiment on production testing and implementation of the systems and introduction the soil tillage and sowing systems of winter wheat are presented. On the results of experimental researches were stated, that the applying the direct seeding of winter wheat using the seeding machine ATD-6.35 contributed to an increase in the indicators of the density of productive stems for 7,4– 20,9 %, a decrease in the grain weight out of 1 ear for 0,11–0,27 g and the weight of 1000 grains for 2,8–4,7 g compared with the use of surface tillage and seeding with seeding machine ATD-6.35 and SZ-3.6. The highest grain yield of winter wheat was formed in the variant that mentioned a surface soil tillage and seeding with ATD-6.35 and was 5,62 t/ha, which was 0,12 and 0,16 t/ha more than the variant using the seeding machine ATD-6.35 without tillage and seeding machine SZ-3.6 on surface tillage. Analysis of winter wheat grain in the phase of full ripeness showed, that the protein and gluten contents of in samples of variants 1 and 2, where the ATD-6.35 was used were higher compared to option 3 and amounted respectively to 12,7–13,3 and 24,0–25,3 % which corresponds to the requirements of grain class 2.

Structural Quality of an Oxisol Under Conventional Soil Tillage and Predecessor Crops in Sugarcane Rotation

Alternating crops at the time of sugarcane rotation can improve soil physical quality, mainly through the action of the root system. The present study aimed to evaluate the impact of crops on the structural quality of a Latossolo Vermelho Distroferrico (Rhodic Hapludox) in a conventional soil tillage system under sugarcane rotation. The experimental design was a randomized block design, with five replicates. The five studied crops were Crotalaria juncea, Crotalaria ochroleuca, Helianthus annuus (sunflower), Glycine max (L.) Merrill (soybean), and Sorghum bicolor (L.) Moench, sorghum variety saccharine BRS 506, in addition to a fallow treatment. After the vegetative cycle of the crops, undisturbed soil samples were collected at two depths (0.15 and 0.25 m). The predecessor crops to the sugarcane plantation altered the physical water soil attributes at both the evaluated depths. The C. juncea crop increased the least limiting water range, but reduced the soil load-bearing capacity. The sorghum variety saccharine under conventional soil tillage exhibited the highest load-bearing capacities, but was associated with the lowest soil structural quality.

Урожайность и экономическая эффективность яровой пшеницы, возделываемой по различным технологиям

Яровая пшеница является доминирующей культурой в структуре использования пашни и посевных площадей в хозяйствах лесостепи Волго-Вятского региона. Важнейшим элементом и первоначальным звеном технологии возделывания любой полевой культуры является обработка почвы. Основным препятствием внедрения минимизации обработки почвы является ухудшение фитосанитарного состояния посевов. Исследование различных технологий обработки почвы и их влияние на урожайность и экономическую эффективность яровой пшеницы проводили на опытном поле Нижегородской области в 2014 – 2016 гг. Сравнивали традиционную зяблевую вспашку на 14 – 16 см и обработку почвы по no-till технологии. Изучали возможность минимизации системы обработки почвы под яровую пшеницу в звене зернотравяного севооборота. Урожайность яровой пшеницы при возделывании по no-till технологии ниже — 1,00 – 1,67 т/га, чем при традиционной зяблевой вспашке — 1,75 – 1,84 т/га. По системе no-till по сравнению с традиционной вспашкой денежно-материальные затраты на 1 га минимальны с внесением и без внесения минеральных удобрений — соответственно 10,21 тыс. и 6,21 тыс. руб./га против 14,21 тыс. и 12,1 тыс. руб./га. Рентабельность по системе no-till, наоборот, выше — 30,85 % с внесением и 28,82 % без внесения минеральных удобрений против 3,59 и 14,66 % соответственно при традиционной зяблевой вспашке. Возделывание яровой пшеницы по ресурсосберегающей no-till технологии экономически эффективнее технологии с традиционной обработкой почвы, несмотря на более высокие показатели пораженности болезнями и засоренности пшеницы.

Temporal Variation of Soil Physical Quality under Conventional and No-Till Systems

ABSTRACT: Determination of soil physical quality (SPQ) is very important because it is related to many important soil processes. However, it is not clear which indicators should be considered in this evaluation, and information about temporal variation of SPQ under different soil tillage systems is scarce. The aim of this study was to determine the effects of no tillage (NT) and conventional tillage (CT) on temporal variation of capacity SPQ indicators [bulk density (BD), macroporosity (Pmac), air capacity (AC), plant [...]

Assessment of ecological and economic efficiency of agricultural lands preservation

The article substantiates the necessity to define and generalize the criteria for assessing the ecological and economic efficiency of using agricultural lands. Due to the transition of the agro-industrial complex to private forms of management, the problems of forming a strategy of rational, ecologically safe and sustainable development of land use in Ukrainian agriculture became of paramount importance. Therefore, systematic studies on the assessment of the ecological and economic efficiency of the agricultural land use need to be conducted. Harmonization of ecological and economic interests is of particular importance in the context of ensuring the conservation, resource-saving and reproductive nature of the agricultural land exploitation.A scientific study found that in Ukraine, the agrarian sector of the economy provides about 47% of GDP, but the question arises: At what price are these achievements given to us? Agricultural land development exceeds environmentally sound standards. Excessive cultivation of the territory leads to an annual increase of eroded lands by 80-90 thousand hectares. Land use is recognized as environmentally unstable, and there is a steady tendency to deteriorate the quality of soil. Each second hectare of cultivated land is erosion-hazardous, that is, these soils are subject to water and wind erosion. In this regard, it is recommended to introduce the world-wide experience of Climate Smart Agriculture (CSA), which provides an opportunity to provide food security to the country and to limit the negative impact of the environment, based on the introduction of organic production.It is proved that regardless of the size of farms and forms of management using resource-saving no-till technologies, enterprises received low cost of grown products, providing profitable activities. Ecological compatibility of the technology provides energy savings of at least 30% in comparison with traditional farming systems, the accumulation of not less than 30-40% of plant residues on the soil surface after harvesting of the predecessor, provides protection of the soil from wind and water erosion by minimizing the amount and depth of technological operations.It is confirmed that the most widespread evaluation of the agricultural lands use is the evaluation of the results of their use through volumes of gross and commodity products, income, and production profitability. The criteria for the environmental effectiveness of agricultural land use should be: the degree of functional use of land resources, ecological stability, the level of anthropogenic loading, the degree of erosional feature of land, etc.According to the study results, it was established that one of the main areas of agriculture is the application of minimal tillage in crop rotation, i.e. resource-saving no-till technology.The economic feasibility of technologies based on the use of different soil tillage systems has been confirmed.

Importance of Agronomic Practice on the Control of Wheat Leaf Diseases

Soil tillage and crop rotation are considered important tools in wheat leaf disease control; however, the results of investigations are inconsistent. The aim of the present study was to determine the effect of the soil tillage system and cropping sequence on the development of winter wheat leaf diseases in 2012–2017. The disease development was assessed in a two-factor experiment: (a) soil tillage system; and (b) crop rotation. Foliar fungicides were used uniformly in all variants. The results showed that tan spot (caused by Pyrenophora tritici-repentis) dominated in 2012, 2013, and 2016, but the level of Septoria tritici blotch (Zymoseptoria tritici) was essentially lower and exceeded the severity of tan spot only in 2015. The agronomic practice used significantly influenced only the development of tan spot. Reduced soil tillage and continuous wheat sowing substantially increased tan spot severity, especially when both practices were used simultaneously. Short crop rotation (only wheat and oilseed rape) provided sufficient control of tan spot in ploughed fields, whereas in non-ploughed fields, the level of this disease did not decrease. The results could be explained by differences in the pathogens’ life cycle: P. tritici-repentis ascospores in wheat debris is the main source of infection; in contrast, Z. tritici spreads by conidia from living plants.

The effect of soil tillage system and weeding time on the growth of weed and yield of soybean (Glycine max (L.) Merril)

The growth and yield of soybeans can decrease due to competition from weeds. Various efforts have been made to control the growth of weeds such as land preparation and weeding periods. An experiment to study the effect of soil tillage systems and weeding time on the growth of weeds and soybean crop yield ( Glycine max (L.) Merril) has been done in Wringinsongo Village, Tumpang Sub-District, Malang Regency from February to May 2017. The split-plot design with three replicates was used with the soil tillage system as the main plot consisting of three levels, T0: no tillage, T 1 : minimum tillage, and T 2 : conventional tillage, and weeding time as the sub plot consisting of 4 levels, P 0 : no weeding, P 1 : weeding 1 time, P 2 : weeding two times and P 3 : weeding three times. The results showed that the dominant weed species before treatment were Amaranthus spinosus (Spiny amaranth), Cynodon dactylon (Bermuda grass), Cyperus rotundus (Purple nutsedge), Ageratum conyzoides (Billygoat weed ), and Portulaca oleracea (Common purslane). After treatment, the dominant weed species were Cyperus rotundus (Purple nutsedge), Amaranthus spinosus (Spiny amaranth), Ageratum conyzoides (Billygoat weed ), Physalis peruviana (Cape gooseberry), and Eclipta alba (False daisy). There was no significant difference of the dry weight of weeds in conventional tillage followed by weeding 3 times at 15, 30 and 45 days after planting, and minimum tillage and no tillage. For the yield of soybeans, conventional tillage followed by weeding 3 times at 15, 30 and 45 days after planting were not significant with that of minimum tillage. The yield of soybeans was lower than that of with no tillage and no weeding.

Pengaruh Sistem Olah Tanah dan Residu N Tahun ke–29 pada Beberapa Sifat Kimia Tanah dengan Tanaman Indikator Leguminosa

Degradasi lahan akibat pengolahan tanah intensif secara terus menerus dapat menurunkan produksi pertanian. Penelitian ini bertujuan untuk mendapatkan pengaruh sistem olah tanah, pengaruh berbagai dosis pupuk N pada sifat kimia tanah, dan pengaruh antara sistem olah tanah dan residu N pada sifat kimia tanah tahun ke-29 dengan tanaman indikator leguminosa. Penelitian dilakukan di Politeknik Negeri Lampung mulai dari Mei 2016 sampai dengan November 2016. Penelitian menggunakan Rancangan Acak Kelompok dengan dua faktor. Faktor pertama adalah berbagai sistem olah tanah yang terdiri atas olah tanah intensif (OTI), olah tanah minimum (OTM), dan tanpa olah tanah (TOT). Faktor kedua adalah residu pupuk N (Urea) yang diberikan pada tanaman sebelumnya, yang terdiri atas 3 taraf, yaitu 0kg N/ha (N0), 100 kg N/ha (N1), dan 200 kg N/ha (N2). Perlakuan diulang empat kali. Peubah yang diamati yaitu pH, C-organik, Nitrogen total, P tersedia (H2O), kalium tersedia, dan bobot tajuk. Data di analisis dengan analisis ragam diikuti dengan uji BNT pada taraf α = 0,05. Hasil penelitian menunjukkan bahwa tidak terdapat interaksi antara sistem olah tanah dengan residu pupuk N. Tanpa olah tanah menghasilkan P tersedia tertinggi (10,713). Residu nitrogen dengan taraf dosis 200 kg N/ha menghasilkan pH terendah (5,980).

Arable weed species associated with soil tillage systems under Mediterranean conditions

AbstractTillage soil erosion is seen as a great problem in the Mediterranean region and is worsened by the climatic conditions. Previous studies have shown a decrease in biodiversity in arable lands across Europe. Weeds are a major component of biodiversity within agro‐ecosystems, but few studies have aimed to associate weed species with soil tillage intensity. We performed an analysis to test the potential short‐term effects of different tillage systems on weed species under our study conditions. The emerged weed data were measured, comparing a conventional tillage system with conservational tillage systems (minimum tillage and no tillage) in 2 cropping systems (monoculture wheat and a rotation scheme of barley–legume–wheat–fallow). Compared with the tilled soil, higher weed density and weed species richness were observed in the conservation tillage plots. The weed density and weed species richness in the monoculture system were higher compared with those in the crop rotation system. We used classification and regression trees to analyze the relationship between the soil tillage systems and the weed community, taking into account the climatic conditions. The results indicate that different soil tillage systems produced tree models: Silene vulgaris (L.) was associated with the MT system and high and irregularly distributed rainfall; Hypecoum imberbe Sm. and Hypecoum procumbens (L.) were linked to MT plots with low and well‐distributed precipitation rates; and Cardaria draba (L.) was present all years independently of climatic conditions but was never found in the NT system, so its presence could be regarded as an indicator of tillage intensity.