Clogging of crops and productivity of 5-field crop rotation against the background of different intensity of the main cultivation of chernozem soil

Formulation of the problem. Crop rotations of modern field agriculture should be developed according to the principle of classical fruit change, which is an important factor in the high productivity of individual crops on different agro-backgrounds, which can be different ways of the depth of the main tillage. Verification of the latter was the main task of our research. Conditions and methodology. Field studies were carried out in a stationary experiment on podzolized chernozem with a 5-field crop rotation with such an alternation of spring crops: soybeans – rapeseed – wheat – oil flax – barley. The experiment compared the effect of plowing and flat-cut loosening at 15–17, 20–22 and 25–27 cm on the weediness of crops, crop yield and the productivity of crop rotation in terms of the yield of feed units and assimilated protein. Research results. It has been established that a significant part of weed seeds after flat-cutting loosening is concentrated in a layer of 0–10 cm, from where, under favorable moisture conditions, it can germinate with the formation of seedlings, which can bloom before cold weather and replenish the stock of weed seeds in the soil. During moldboard plowing, weed seeds are evenly distributed over the entire arable layer, as a result of which it can be half as much in the 0-10 cm layer as after non-moldboard plowing. Therefore, the actual weediness of crops cultivated in crop rotation has always been higher after flat-cutting loosening: soybeans – by 22.1 %, rapeseed – by 72.6 %, and wheat, oil flax and barley – 15.0, respectively; 20.4 and 20.3%. On average for the crop rotation, this increase averaged 25.2 % over three years. A decrease in the depth of cultivation also caused contamination of crops, and its deepening as a whole in the crop rotation had a positive effect on the cleanliness of crops from weeds. The level of weediness of crops of cultivated crops at the beginning of the growing season should be considered a determining factor in the formation of the productivity of these crops due to the presence of a strong and very strong correlation between these indicators. Wheat was the most productive in terms of the yield of feed units, and soy was the most productive in terms of the yield of digestible protein. This applied to both methods or techniques of the main processing, and individual crops against the background of plowing had an advantage in both productivity indicators over flat-cut loosening. The productivity of crops and crop rotation was higher against the background of deep cultivation compared to medium and shallow cultivation. Conclusions. The use of flat-cut loosening instead of moldboard plowing, as well as a decrease in the depth of both methods of processing, is accompanied by a significant increase in the contamination of crops. As well as a decrease in the yield of the main products and a noticeable decrease in the productivity of a 5-field crop rotation in terms of the yield of feed units and assimilated protein.

Cleaning of vegetable seeds on a pneumatic sorting table

Семенной ворох с поля никогда не бывает чистым. В процессе уборки семян в семенной ворох попадают различные примеси – семена сорняков, различные обломки частей растений, минеральные частицы: комочки земли, камешки и др. Очистка семенного вороха до регламентированных показателей, предусмотренных в нормативном документе, – основная задача послеуборочной доработки семян. Примеси, которые отличаются размером от семян основной культуры, легко удаляются на ветрорешетных машинах. Полностью удалить все примеси на ветрорешетных машинах невозможно. Поэтому существует необходимость во вторичной, более качественной очистке семенного вороха. Пневмосортировальные столы способны разделить семенной ворох по плотности семян. В результате дополнительной вторичной очистки семян можно повысить чистоту семян, которая необходима для безотказной работы современных высевающих аппаратов. Пневмосортировальный стол ПСС-1 имеет ряд настроек, которые меняются оператором в зависимости от культуры. Основные настройки: подача семян, регулировка заслонки вентилятора, изменение продольного и поперечного угла наклона рабочей деки, частота колебания рабочей деки, регулируемые заслонки приемника семян. Все настройки могут быть оперативно изменены оператором технологического процесса очистки. Использование пневмосортировального стола во вторичной очистке семенного вороха возможно на различных овощных культурах. В процессе очистки семян на пневмосортировальном столе из семенного вороха удаляются вместе с легковесными примесями, обломками стебельков, листьев, стручков и прочими, удаляются и легковесные невызревшие семена, что способствует повышению всхожести получаемых после очистки семян. The resulting seed heap from the field is never clean. In the process of harvesting seeds, various impurities are found in the seed pile. As impurities in the seed heap, there may be weed seeds, various fragments of plant parts, mineral particles: lumps of earth, pebbles and others. Cleaning the seed pile to the regulated indicators provided for in the regulatory document is the main task of post-harvest seed refinement. Impurities that differ in size from the seeds of the main crop are easily removed by wind-screen machines. It is impossible to completely remove all impurities on windscreen machines. Therefore, there is a need for a secondary, better cleaning of the seed pile. Pneumatic sorting tables are able to divide the seed pile according to the density of seeds. Because of additional secondary cleaning of seeds, it is possible to increase the purity of seeds, which is necessary for the trouble-free operation of modern sowing machines. The PSS-1 pneumatic sorting table has a number of settings that are changed by the operator depending on the culture. Basic settings: seed feeding, fan flap adjustment, changing the longitudinal and transverse angle of inclination of the working deck, the oscillation frequency of the working deck, adjustable shutters of the seed receiver. The operator of the cleaning process can quickly change all settings. The use of a pneumatic sorting table in the secondary cleaning of the seed pile is possible on various vegetable crops. In the process of cleaning seeds on a pneumatic sorting table, fragments of stems, leaves, pods and others are removed from the seed pile together with lightweight impurities, and lightweight unripe seeds are also removed, which helps to increase the germination of seeds obtained after cleaning.

Giant sumpweed (Cyclachaena xanthiifolia (Nutt.) Fresen.): seed stocks, seedling dynamics, methods control

Goal. To assess the degree of danger of contamination of the sowing layer and an increase in stocks of Giant sumpweed seeds in the soil, the timing and dynamics of seedlings emergence, to develop a control pathway aimed at their reduction. Methods. The studies were carried out by route-expeditionary surveys and field experiments. The potential soil contamination was determined washing weed seeds from soil samples. Weeds were counted in 4—6-single repetitions. Results. In ruderal biotopes, the infestation of 0—20 cm of the soil layer by weed seeds has not changed since 2009 and amounted to 244.6—384.1 thousand pcs./m2. At the same time, the infestation of soils with Giant sumpweed seeds increased 2.0—2.7 times. In crops of cultivated plants, the total weediness of the soil increased by 1.8—3.5 times, and Giant sumpweed — by 4.7—12.1 times and reached 25.0—85.0 and 14.5—15.5 thousand pcs./m2, respectively. Seed germination of Giant sumpweed was observed only in the spring and early summer periods. In the Dry and Southern Steppe, Giant sumpweed emerged in the middle-end of March, in the Northern Steppe — during April, Forest-Steppe — from early May to early June. In crops of cultivated plants the density of young crops of Giant sumpweed did not exceeded 23—62 pcs./ m2, and on uncultivated lands — from 636 to 862 pcs./m2. On uncultivated lands the effective control in crops of Giant sumpweed was carried out by mowing weeds, in crops of cereals — by herbicides of leaf action in the tillering stage, late arable crops by pre- and after emergence harrowing combined with inter-row cultivation. Conclusions. Potential soil infestation by seeds of Giant sumpweed in ruderal biotopes since 2009 increased by 2.0—2.7 times, and in crops of cultivated plants — by 4.7—12.1 times and reached 25.0—85.0 and 14.5—15.5 pcs./ m2 thousand, respectively. Seed germination of Giant sumpweed occurred only in spring and early summer. The number of seedlings on ruderal areas reached 636—862 plants/m2, and in crops — 23—62 plants/m2. Effective control of Giant sumpweed on uncultivated lands was achieved by mowing weeds, in sowing of grain crops with leaf herbicides in the tillering phase, row crops — by pre-emergence and post-emergence harrowing in combination with inter-row cultivation.

The Role of Weed Seed Contamination in Grain Commodities as Propagule Pressure

The international grain trade is a major pathway for the introduction of alien plants because grain commodities can be contaminated with various weed seeds. To evaluate how alien weed seeds derived from imported grain commodities affect local vegetation in international trading ports, we conducted a vegetation survey on a set of grain landing ports and non-grain landing ports in nine regions throughout Japan to compare the vegetation between these two types of ports. We also surveyed weed seed contamination of wheat imported into Japan, and the contamination rate was calculated for each species based on our survey and previous studies on weed seed contamination. The vegetation clearly differed between the grain landing ports and the non-grain ports. In the grain landing ports, alien species were more abundant than in non-grain landing ports. All indicator species of the grain landing ports were reported to be contaminants in grain commodities. Furthermore, there was a tendency for the more abundant species at the grain landing ports to show higher contamination rates in grain commodities. These results indicate that contaminant seeds spill from imported grain in grain landing ports, and highly contaminated species are likely to become established. We clearly show that weed seed contamination in grain commodities plays an important role in propagule pressure. Gathering information about the prevalence of weeds in grain-exporting countries and monitoring the weed species composition in imported grain commodities is becoming increasingly important for predicting the unintentional introduction of troublesome weeds and identifying effective weed management options.

Evaluation on maturity and stability of organic fertilisers in semi-arid Ethiopian Rift Valley

Case studies that have comprehensively examined local organic fertilisers (OFs) for their maturity and stability are rare in sub-Saharan Africa. Farmers in the semi-arid Ethiopian Rift Valley use indigenous compost (kosi) and household wastes for OFs. With the entry of fast compost that was introduced by the administration, maturity and stability of these OFs were assessed. Their maturity was assessed by: monitoring pile temperature and volume, pH, organic matter and total nitrogen contents, and carbon to nitrogen ratio; determination of NO3– to NH4+ ratio; and respirometric measurement of CO2 evolution. Their stability was assessed by weed seed germination tests and phytotoxicity bioassays. Weed seeds that were originally contained in the feedstock of the kosi and fast compost samples became inactive during the composting process. The CO2 evolution tests and phytotoxicity bioassays indicated a probable presence of some phytotoxic compounds in the kosi. Mature kosi and immature kosi in a kosi pile should be mixed before the field application. Some samples (15%) of the household wastes contained weed seeds. The combination of several assessment methods used in this study and determination methods for nitrogen components using RQ-flex is considered to be effective for on-site quality assessment of OFs in sub-Saharan Africa.