The Influence of Cascade Reservoir Construction on Labile Phosphorus in the Sediment of Lancang River

The influence of cascade reservoirs construction on labile phosphorus (P) is an important scientific problem in the Lancang River. The concentration of labile P in cascade deep-water reservoirs were determined, and the influence of cascade reservoirs construction on the DGT-labile P was analyzed. The construction of cascade reservoirs led to significant differences in concentrations of DGT-labile P, which in the upstream of Xiaowan (XW) Reservoir were differences from that in the downstream Nuozhadu (NZD) Reservoir. The P diffusion fluxes in XW Reservoir were − 8.59–250.50 ng·cm− 2·d− 1, and that in NZD Reservoir were 3.82–24.80 ng·cm− 2·d− 1. The P pollution of XW Reservoir was higher, highlighting the importance of controlling P pollution of XW Reservoir. The construction of cascade reservoirs had made the release of DGT-labile P more dependent on the reductive dissolution of Mn oxides. The early diagenesis transformed bio-availability P (BAP) remobilization into DGT-labile P that made the increase of DGT-labile P/BAP with depth. However, the DGT-labile P/BAP of upstream XW Reservoir was 7.8 times larger than that of downstream NZD Reservoir, which indicated that the construction of cascade reservoirs weakened the remobilization of P in sediment.

THE EFFECT OF FERILIZERS ON SOYBEAN PRODUCTIVITY UNDER IRRIGATION

We carried out research to study the effect of various conditions of mineral nutrition on the soybean productivity under irrigation in the southern forest-steppe of Western Siberia. Under conditions of regulation of water availability, an increase in seed yield (from 1.84 to 2.19 t/ha, or by 18 %) was due to the aftereffect of backgrounds with an increased phosphorus content. The application of phosphorus-containing is effective against the backgrounds with an average availability of labile phosphorus – the soybean seed yield increased from 1.44 to 1.74 t/ha, or by 21 %. In general, an improvement in the conditions of mineral nutrition by pre-sowing application of ammonium nitrate and ammonium molybdate (N30+Mo) against the backgrounds with increased and high Р2О5 content provided an increase in the yield of soybean seeds from 1.44 to 2.44 t/ha, or by 69 %.

Inorganic Phosphorous, Lime and Vermicompost Induced Changes on Phosphorus Fractions and Other Properties of Acidic Soil of Cheha District, Ethiopia

Background: In acid soils, soluble inorganic phosphorus is fixed by aluminum and iron, so that phosphorous availability to plant would be inhibited. Thus, an incubation study was conducted to evaluate the effects of lime, vermicompost, and mineral P fertilizer on the distribution of P fractions and oxalate and dithionite extractable aluminum and iron. The treatments consisted of three rates of phosphorous (0, 74.51 and 149.01 kg P ha-1), three rates of vermicompost (0, 5 and 10 ton VC ha-1) and four rates of lime (0, 5.70, 9.20, and 11.50 ton CaCO3 ha-1). The experiment was laid out as a complete randomized design in a factorial arrangement. Results: Combined application of lime, vermicompost and mineral P significantly increased (p<0.05) labile phosphorus fractions and decreased potential sorption capacities of the soil. As the increased soil pH, reduced exchangeable acidity and oxalate extractable Fe and Al the integrated applications of these amendments fixed aluminum and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool compared to sole application of the amendments. Conclusions: Combined applications of lime, vermicompost and inorganic P to acidic soils of Goha-1 in Cheha district could convey enhanced amount of available P and ensures the maintenance of higher levels of labile P. It might also contribute towards meeting crop P requirements.

The effectiveness of the minimum norms of Goal 2E on onions in an annual culture

Лук репчатый – важнейшая овощная культура в стране. Величина и качество урожая в значительной мере определяется эффективностью борьбы с сорняками. При этом необходим поиск новых более эффективных схем применения гербицидов, обеспечивающих снижение их норм внесения в сочетании с повышением эффективности. На луке необходимо очищать посевы от сорняков в период флаг-листа культуры до двух настоящих листьев, а сорняки – в фазе семядоли – одного настоящего листа. Злаковые сорняки уничтожают применением широкого ассортимента граминицидов. Двудольные – как в культуре предшественника в севообороте, так и по вегетирующим растениям лука. В 2019–2020 годах были испытаны системы гербицидов, включающие внесение Реглон Форте 2,0 л/га за 1–3 дня до всходов лука в сочетании с применением Гоал 2Е в нормах 0,2, 0,25 и 0,3 л/га в фазу первого настоящего листа у лука (длина 3,2–3,7 см). Опыты проводили на опытном поле Всероссийского научно-исследовательского института овощеводства – филиале Федерального научного центра овощеводства (Московская область). Почва участка – аллювиальная, луговая, среднесуглинистая с содержанием гумуса 3,0–3,2%, рН солевой вытяжки 5,9, хорошо обеспечена подвижным фосфором (22–26 мг на 100 г почвы) и слабо калием (12–16 мг на 100 г почвы). Агротехника возделывания при капельном орошении была общепринятой для Нечерноземной зоны России. Учет эффективности проводили согласно стандартных методик. Размер учетных делянок – 12 м2. Повторность опытов четырехкратная. Установлено, что на посевах лука со средним и слабым уровнем засоренности, перспективны послевсходовые обработки Гоал 2Е в оптимальной норме 0,25 л/га начиная с фазы первого настоящего листа культуры по сорнякам в ранней стадии развития на фоне предвсходового внесения Реглон Форте 2,0 л/га. При этом главный фактор успеха применения Гоал 2 Е в первую очередь – фаза развития сорняков. Максимальный эффект можно достигнуть, когда значительное большинство из них будет в момент обработки в фазе семядолей. Onions are the most important vegetable crop in the country. The size and quality of the crop is largely determined by the effectiveness of weed control. At the same time, it is necessary to search for new more effective schemes for the use of herbicides, which ensure a reduction in their application rates in combination with an increase in efficiency. On the onion, it is necessary to clear the crops from weeds during the flag-leaf culture to two real leaves, and weeds – in the cotyledon phase – one real leaf. Cereal weeds are destroyed by using a wide range of graminicides. Dicotyledons – both in the culture of the predecessor in the crop rotation, and on vegetative onion plants. In 2019–2020, herbicide systems were tested, including the introduction of Reglon Forte 2.0 l/ha 1–3 days before onion shoots, in combination with the use of Goal 2E in the norms of 0.2, 0.25 and 0.3 l/ha in the phase of the first real leaf in onions (length 3.2–3.7 cm). The experiments were carried out at the experimental field of All Russian Research institute of Vegetable Growing – branch of Federal Scientific Centre of Vegetable Growing (Moscow region) The soil of the site is alluvial, meadow, medium loamy with a humus content of 3.0–3.2%, a pH of salt extract of 5.9, well provided with labile phosphorus (22–26 mg per 100 g of soil) and weakly potassium (12–16 mg per 100 g of soil). The agricultural technique of cultivation with drip irrigation was generally accepted for Non-chernozem zone. The efficiency was taken into account according to standard methods. The size of the accounting plots is 12 m2. The repetition of experiments is fourfold. It was found that on onion crops with medium and low levels of infestation, post-emergence treatments of Goal 2E in the optimal rate of 0.25 l/ha are promising, starting from the phase of the first real leaf of the crop for weeds in the early stage of development against the background of pre-emergence application of Reglon Forte 2.0 l/ha. At the same time, the main factor for the success of the use of Goal 2 E, first of all, is the phase of weed development. The maximum effect can be achieved when a significant majority of them will be in the cotyledon phase at the time of processing.

Формирование продуктивных качеств картофеля разных сортов в условиях Костромской области

В 20172018 гг. в условиях Костромской области было проведено эколого-географическое испытание 10 сортов картофеля различных групп спелости селекции ФГБНУ ВНИИКХ: Метеор, Башкирский, Красавчик, Варяг, Вымпел, Фаворит, Великан, Колобок, Накра, Никулинский. Почва опытного участка дерново-подзолистая, легкосуглинистая, слабокислая, хорошо окультуренная, с высоким содержанием гумуса (2,53), подвижного фосфора (324 мг/кг почвы) и обменного калия (181,4 мг/кг почвы). Предшественник кукуруза на зелёную массу. Схема посадки 7030 см, площадь делянки каждого сортообразца 4,2 м2, повторность трёхкратная, расположение сортов систематическое. В 2017 году урожайность сортов ранней группы спелости составила 21,2936,61 т/га, а среднеспелой группы 29,0760,36 т/га. В 2018 году разница в урожайности была менее заметна и составила 19,4132,32 т/га и 33,2445,11 т/га соответственно. В целом урожайность разных сортов в 2018 году была более выровненная, чем в 2017 году, что можно объяснить климатическими условиями. Содержание сухого вещества и крахмала составило в 2017 году 16,526,9 и 10,821,2, в 2018 году 15,428,2 и 9,722,5 соответственно. В среднем за два года наивысшая урожайность и содержание сухого вещества и крахмала в раннеспелой группе сортов было отмечено у сорта Красавчик. В группе среднеспелых сортов самая высокая урожайность зафиксирована у сорта Великан, а самое высокое содержание сухого вещества и крахмала у сорта Накра.In 20172018 in the conditions of the Kostroma region an ecological and geographical test of 10 potato varieties of various maturity groups of the FSBSI Lorch Potato Research Institute was conducted: Meteor, Bashkirsky, Krasavchik, Varyag, Vympel, Favorit, Velikan, Kolobok, Nakra, Nikulinsky. The soil of the experimental plot was soddy podzolic, light loamy, subacid, well cultivated with a high content of humus (2.53), labile phosphorus (324 mg/kg of soil) and exchangeable potassium (181.4 mg/kg of soil). The predecessor was corn for green mass. The planting system was 70 30 cm, plot area of each variety specimen was 4.2 m2, it was repeated three times, the arrangement of varieties was systematic. In 2017 the yield of varieties of the early ripening group was 21.2936.61 t/ha and the mid-ripening group was 29.0760.36 t/ha. In 2018 the difference in yield was less noticeable and amounted to 19.4132.32 t/ha and 33.2445.11 t/ha respectively. In general the yield of different varieties in 2018 was more leveled than in 2017 which can be explained by climatic conditions. The dry matter and starch content in 2017 amounted to 16.526.9 and 10.821.2, in 2018 15.428.2 and 9.722.5, respectively. On average over two years the highest yield and dry matter and starch content in the early ripening group of varieties were noted in the Krasavchik variety. In the group of mid-ripening varieties the highest yield was recorded in the Velikan variety and the highest dry matter and starch content was in the Nakra variety.

Determig the reference value of Cesium-137 specific activity on arable slopes in the periglacial area of the Upper Oka basin: application of satellite images, GIS and soil agrochemical indicators

The paper deals with the issues of determining the reference value of specific activity of cesium-137 of Chernobyl origin when applying the radiocesium method to assess the loss of gray forest soil in the areas of spread of the microrelief of paleocryogenic origin in the periglacial region of the upper Oka basin. Paleocryogenic microrelief is recognized in spring satellite imagery available on Google EarthTM. The necessity of choosing a reference plot for a specific field that differs in microrelief, exposure, and the nature of soil cultivation is substantiated. The authors analyze the data, which they obtained during the field research in 2016-2019, on three agricultural fields located on the arable slopes of the northern and southern exposure in the upper Oka basin within the Orel district of the Orel Region. Three experimental plots, selected in close proximity to one another, differed both in exposure and in the content of humus, labile phosphorus and radiocaesium in the arable layer. Layer-by-layer soil sampling at block elevations within the reference plots located on watershed surfaces, gamma-spectrometric and agrochemical analyzes of soil samples allowed us to draw a number of systematically important conclusions. The first is that the reference value of radiocaesium in the arable layer should be determined within block elevations on the watershed surface of the slope or on inter-valley micro-water divisions on the water-divide surface (if it is not possible to select a reference plot on the watershed surface). The second is that the dimensions of the reference plots are determined by the size of the block elevations (the sizes of blocks in the area under study are 10-20 m). The third is that the reference value of radiocaesium should be determined individually for each field that differs in exposure and in the nature of the soil treatment. In the experimental plot, the reference value of the specific activity of cesium-137 increases in the following order: a field located on the water-divide surface of the northern exposure slope, with a grain rotation, with regular fertilizing (130.5 Bq/kg) — a field located on the watershed surface of the eroded slope southern exposure (174.7 Bq/kg) — a field located on the water-divide surface of a less fertilized and less eroded slope of the northern exposure (180 Bq/kg). The results of the study show that the use of the radiocaesium method in periglacial areas requires testing a fundamentally new approach to its implementation: at the stage of determining the reference value of radiocaesium, it is necessary to take into account the polygonal-block structure of the watershed surfaces.