Experimental Plots Research Articles

Search for sources of resistance to leaf diseases among present winter bread wheat varieties in the southern part of the Rostov region

The purpose of the current work was to search for sources of winter wheat varieties’ resistance to the most common pathogens of the area under artificial infectious backgrounds and recommend them for inclusion in the breeding process. The study was carried out on the experimental plots of the laboratory for plant immunity and protection of the FSBSI Agricultural Research Center “Donskoy” in 2021–2023. In order to expand the genetic diversity in immunity of newly developed varieties, it is necessary to use new sources of resistance. The objects of study were 78 winter wheat varieties from interstation variety testing, representing various breeding institutions in Russia and some foreign varieties. The study material was presented by the North Caucasian populations of pathogens of such wheat leaf diseases as powdery mildew, brown and yellow rust, and leaf spot (Septoria). Infectious backgrounds were formed according to generally accepted methods, using spore material of pathogens both stored and collected from crops in the previous year (types of rust) and collected from overwintered plants in the spring (powdery mildew, leaf spot). Weather conditions varied across the years of study (mainly in the autumn), but the damage to susceptible test varieties in the experiments was maximum. As a result of the study of the varieties on their resistance to one pathogen, there have been identified 23 varieties resistant to powdery mildew, 56 ones to leaf rust, 47 ones to yellow rust, 8 varieties to leaf spot. There has been given a characteristic of varieties according to various degree of resistance or susceptibility to each pathogen. On the resistance to two pathogens, there have been identified 17 varieties resistant to brown and yellow rust, 2 varieties resistant to brown rust and powdery mildew, 2 varieties resistant to yellow rust and powdery mildew, 1 variety resistant to brown rust and leaf spot. Ten varieties have shown resistance to no one pathogen, but they have had moderate resistance or moderate susceptibility to several other pathogens. 20 varieties were resistant to three diseases in various combinations, and 16 of them were resistant to brown, yellow rust, and powdery mildew. One variety ‘MV Nador’ from Hungary showed resistance to all 4 pathogens. All resistant varieties identified in the study can replenish the supply of winter wheat sources to the complex of leaf diseases for breeding purposes or be used in integrated crop protection against leaf diseases.

The effect of some morphological traits of collection alfalfa samples on productivity through a three-year growing cycle

The current paper has presented the study conducted in the alfalfa collection nursery on the experimental plots of the Agricultural Research Center “Donskoy” in the period from 2021 to 2023. The purpose of the study was to determine the dependence of green mass productivity of collection alfalfa samples on the morphological traits of plants. The object of the study was a collection of alfalfa, consisting of 105 samples developed created at FSBSI ARC “Donskoy”. Sowing was carried out manually, with row spacing of 20 cm. The area of the plots was 1 m2 , with double repetition. The seed-sowing rate for alfalfa was 2 g/m2 . The standard variety was ‘Rostovskaya 90’. As a result, there was revealed that over 3 years the highest mean productivity of alfalfa green mass was formed in two groups of samples according to plant height: 1) 80–85 cm – 8.10 kg/m2 (the samples ‘SGP-424’, ‘SPCh 401/2000’); 2) 105–110 cm – 7.88 kg/m2 (‘SGP-162’, ‘SGP-189’, ‘SGP-175’, etc.). This indicator of alfalfa productivity was the highest (7.81 kg/m2 ) in the optimal values of tillering (15–20 pcs.). The highest alfalfa green mass productivity was formed by the samples with foliage of 48–50 % and 42–44 %. The green mass productivity of alfalfa samples varied within the range of 3.33–10.49 kg/m2 . There have been identified 7 samples which productivity ranged from 9.09 kg/m2 to 10.49 kg/m2. There have been selected the samples that combined the highest green mass productivity with tallness and high foliage of plants, as well as the greatest leaf length and hay yields.

High-throughput physiological phenotyping of crop evapotranspiration at the plot scale

ContextPlatforms and instrumentation for Field High-Throughput Plant Phenotyping (FHTPP) are well developed to measure important traits for crop breeding and agronomic studies. However, the research has focused on morphological and spectral traits; and approaches to estimate major physiological processes such as evapotranspiration (ET) for small experimental plots are lacking. ObjectiveIn this study, we put forward a new analytical framework to estimate plot-scale ET by integrating frequent phenotyping data (multispectral and thermal infrared images, canopy reflectance, and LiDAR point clouds) from a FHTPP system (known as NU-Spidercam), the weather data, a simplified two-source energy balance model, and reference ET and crop coefficient calculation. MethodsThe new plot-scale ET method was tested on five field experiments involving maize and soybean crops over two growing seasons, with the different treatment levels of irrigation water. Estimated plot-scale ET was accumulated across the growing reason for each plot, and its association with grain yield was investigated with regression analysis. ResultsThe result showed that plot-scale accumulated ET captured the seasonal trend of plot water use and clearly differentiated the irrigation treatments. Strong linear correlations were observed between plot-scale ET and grain yield, with R2 values ranging from 0.35 to 0.93 (average R2 = 0.71). Plot-scale ET appeared to be a more steady and stronger predictor of grain yield across the seasons than several other morphological and spectral traits including crop height, green pixel fraction, canopy temperature depression, and red-edge normalized difference vegetation index. ConclusionHigh spatial and temporal resolution of the field phenotyping data, along with the new analytical framework reported, successfully estimated ET at small plot scale, which is difficult to achieve with other systems or methods. SignificancesOur work of estimating ET at the plot-scale can be adopt to other ground-based platforms and drones, thus empowers physiologists, breeders, and agronomists for high-throughput phenotyping of water-use related traits and drought response evaluation.

Characterization of Caulimovirid-like Sequences from Upland Cotton (Gossypium hirsutum L.) Exhibiting Terminal Abortion in Georgia, USA.

In this study, we investigated the potential involvement of endogenous viral elements (EVEs) in the development of apical tissue necrosis, resulting in the terminal abortion of upland cotton (Gossypium hirsutum L.) in Georgia. The high-throughput sequence analysis of symptomatic and asymptomatic plant tissue samples revealed near-complete EVE-Georgia (EVE-GA) sequences closely related to caulimoviruses. The analysis of EVE-GA's putative open reading frames (ORFs) compared to cotton virus A and endogenous cotton pararetroviral elements (eCPRVE) revealed their similarity in putative ORFs 1-4. However, in the ORF 5 and ORF 6 encoding putative coat protein and reverse transcriptase, respectively, the sequences from EVE-GA have stop codons similar to eCPRVE sequences from Mississippi. In silico mining of the cotton genome database using EVE-GA as a query uncovered near-complete viral sequence insertions in the genomes of G. hirsutum species (~7 kb) but partial in G. tomentosum (~5.3 kb) and G. mustelinum (~5.1 kb) species. Furthermore, cotton EVEs' episomal forms and messenger RNA (mRNA) transcripts were detected in both symptomatic and asymptomatic plants collected from cotton fields. No significant yield difference was observed between symptomatic and asymptomatic plants of the two varieties evaluated in the experimental plot. Additionally, EVEs were also detected in cotton seeds and seedlings. This study emphasizes the need for future research on EVE sequences, their coding capacity, and any potential role in host immunity or pathogenicity.

Optimized Walking Route Method for Precision Coffee Farming

Coffee production has become increasingly technified in order to optimize the use of inputs and the sustainable use of natural resources. In this context, one way that farmers are investing in their coffee plantations is in the use of precision agriculture techniques, termed precision coffee farming. Over the last few years, research has been conducted to facilitate the application of this technology, and sampling grids with two points per hectare have been recommended by several studies. These georeferenced demarcations in a plot are generally shaped as equidistant squares or rectangles, and the sampling points are located at the centers of these areas. Coffee farmers typically plant their crops following the level line, which greatly hinders the navigation of equidistant points within the field. Thus, the objective of this study was to develop an optimized walking route method to reduce the distance for sampling soil, leaf, and yield attributes. The experimental plots were established in 2000 at Samambaia Farm, located in Santo Antônio do Amparo, Minas Gerais, Brazil, with coffee the cultivar Acaia IAC 479-19, totaling 56.65 ha. The 111 sampling points were distributed in the land following the new method proposed in this study, and, after walking simulations using Farm Works Mapping Software, the new method was compared with the conventional method using the mean displacement between points. The new optimized walking routes method reduced the mean distance traveled to sample the points by 50.1%.

Electrical modeling of an electrochemical sensor operating at the redox cycling mode

In this work, the direct current vs. voltage (DC) characteristics, and the alternate current (AC) impedance of a 1D four-electrode electrochemical cell, operating under redox-cycling conditions, are presented and discussed. The analysis refers to a four-electrode electrochemical system with one positively biased working electrode, one negatively biased working electrode, one auxiliary electrode, and one reference electrode operating in a redox cycling mode. This configuration is useful, for example, for electrochemical biosensors that can benefit from the inherent redox-cycling amplification of the apparatus. An aqueous buffered electrolyte is assumed, containing electrochemically active species that can be oxidized on the anode, with a positive overpotential. Meanwhile, the product of the oxidation reaction can diffuse to the other working electrode which has a negative overpotential, where the product is reduced. The analysis in this paper assumes that oxidation is the dominant mechanism at the anode, reduction is the dominant mechanism at the cathode, and the transport between them is dominated by diffusion. Since it is a 1D model, an ideal lossless redox cycling, i.e. both working electrodes’ currents (anodic and cathodic) are of the same magnitude with opposite signs, is assumed. Next, the small signal (AC) impedance of the electrochemical cell was calculated assuming that the AC signal modifies the oxidation reaction rate at the anode while the reduction reaction rate at the cathode is fixed. The impedance under redox cycling is calculated vs. frequency for various oxidation and reduction rates and both Bodé and Nyquist plots of the impedance are presented. The last part of the paper presents measured data for both DC and AC (i.e. Bodé and Nyquist plots) experiments with interdigitated array (IDA) electrodes, 5 & 10 μm spacing, operating under redox cycling conditions. The DC measurements were conducted in a 6 mM ferricyanide [K3Fe(CN)6] in 0.1 M Phosphate Buffer Saline (PBS) solution, pH 7.4. The AC measurements were conducted in 10 mM & 100 nM ferricyanide (K3Fe(CN)6) in 100 mM KNO3 aqueous electrolyte. A critical discussion follows the results section where the highlights and problems of the models are discussed.

Kombinasi Pupuk Anorganik dan Pupuk Organik Meningkatkan Produksi Tanaman Tomat (Licopersicum esculentum Mill) dengan Pemangkasan Pucuk Apikal

The research aims to determine the effect of a combination of inorganic fertilizer (KNO3) and organic fertilizer (goat manure) on the yield of the Betavila variety when apical shoots are pruned. The research took place from March to October 2019 in Kupang Regency, NTT. The research used RAK with 4 repetitions. The treatments are as follows: M1 = inorganic fertilizer 5 g/l KNO3; M2 = organic fertilizer 20 tons/ha goat manure; M3 = inorganic fertilizer 5 g/l KNO3 + organic fertilizer 30 tons/ha goat manure; M4 = inorganic fertilizer 5 g/l KNO3 + organic fertilizer 15 tons/ha goat manure; M5 = Inorganic fertilizer 3.75 g/l KNO3 + organic fertilizer 15 tons/ha goat manure; M6 = Inorganic fertilizer 3.75 g/l KNO3 + organic fertilizer 30 tons/ha goat manure; M7 = inorganic fertilizer 2.5 g/l KNO3 + organic fertilizer 15 tons/ha goat manure; M8 = inorganic fertilizer 2.5 g/l KNO3 + organic fertilizer 30 tons/ha goat manure. The results of the research showed that the combination of applying inorganic fertilizer and organic fertilizer simultaneously influenced the yield of Betavila variety tomato plants whose apical shoots had been pruned, namely on the number of fruits, fruit weight, and fruit production. Fertilization dose of inorganic fertilizer 3.75 g/l KN03 + organic fertilizer 30 tons/ha goat manure gave the number of fruits per plant (59.63 fruit), fruit production per plant (2.63 kg), and fruit production per experimental plot (50.33 kg) highest.

Do we need post-tree thinning management? Prescribed fire and goat browsing to control woody encroacher species in an Ethiopian savanna

Worldwide, bush encroachment threatens rangeland ecosystem services, including plant biodiversity and forage for livestock. Various control methods for encroaching woody species and restoring herbaceous vegetation exist but have rarely been explored experimentally. We assessed the impact of post-tree thinning management on tree mortality, the herbaceous community, and overall rangeland condition in Borana, an Ethiopian savanna ecosystem. At two 1.4 ha areas of encroached mono-specific Vachellia drepanolobium (whistling thorn) stands, we set up twenty-four 20 × 10 m experimental plots with four post-tree-thinning treatments (goat browsing only (1), prescribed fire (2), fire and goat browsing (3), and control (4) (i.e., no management after tree cutting), with three replications in a complete block design. Over two growing periods, we monitored resulting tree mortality, coppicing, seedling mortality and recruitment, as well as herbaceous layer attributes (diversity, biomass) and overall rangeland condition. All three post-tree thinning management scenarios significantly enhanced tree mortalities, reduced seedling recruitment and increased the abundance of the dominant desirable grass species. Prescribed fire and fire and goat-browsing treatments resulted in significantly greater grass and forb species richness, forb diversity, and biomass, as well as the overall rangeland condition compared to goat browsing only and the control treatment. However, grass species diversity did not respond to treatments. Post-tree management significantly increased tree mortality, reduced seedling recruitment, and increased the abundance of desirable grass species. Our findings strongly suggest that post-thinning management, particularly prescribed fire or a combination of fire and browsing, is highly effective in suppressing woody encroachment and improving biomass and overall rangeland condition.

Pertumbuhan dan Produksi Jagung pada Berbagai Varietas dan Dosis Trichokompos

The productivity of maize as a staple food needs continuous enhancement through various methods, one of which is fertilization. The exploration of diverse fertilizers is expected to help reducing the reliance on increasingly expensive synthetic fertilizers. Fertilization is a crucial practice to improve soil fertility on marginal lands. It refers to land with productivity limitations due to factors such as low soil fertility, poor soil texture, or environmental conditions that do not support optimal plant growth. By providing additional nutrients through trichocompost fertilizer, plants are expected to grow better even under suboptimal soil conditions. This study aims to investigate the effect of trichocompost fertilizer dosage on various maize varieties grown on marginal land. The research was conducted using an experimental design with plot sizes of 3 x 5 meters. The method employed was a factorial Randomized Block Design (RBD) with two factors. The first factor was the dosage of trichocompost (control, 3 tons/ha, and 6 tons/ha), and the second factor was maize varieties (Sinhas1, Nasa29, JH36, Bisi18, and Pioneer27), with each treatment repeated three times, resulting in a total of 45 experimental plots. The parameters tested included plant height, number of leaves, ear height, days to flowering, and fresh ear weight. The results showed that trichocompost had a significant effect on two parameters: the increase in plant height and the number of leaves at 49 days after planting (DAP), as well as the fresh ear weight. The maize variety significantly affected almost all tested parameters.

Spatial heterogeneity of soil moisture caused by drainage and its effects on cadmium variation in rice grain within individual fields

Paddy drainage is the critical period for rice grain to accumulate cadmium (Cd), however, its roles on spatial heterogeneity of grain Cd within individual fields are still unknown. Herein, field plot experiments were conducted to study the spatial variations of rice Cd under continuous and intermittent (drainage at the tillering or grain-filling or both stages) flooding conditions. The spatial heterogeneity of soil moisture and key factors involved in Cd mobilization during drainages were further investigated to explain grain Cd variation. Rice grain Cd levels under continuous flooding ranged from 0.16 to 0.22 mg kg−1 among nine sampling sites within an individual field. Tillering drainage slightly increased grain Cd levels (0.19–0.31 mg kg−1) with little change in spatial variation. However, grain-filling drainage greatly increased grain Cd range to 0.33–0.95 mg kg−1, with a huge spatial variation observed among replicated sites. During two drainage periods, soil moisture decreased variously in different monitoring sites; greater variation (mean values ranged from 0.14 to 0.27 m3 m−3) was observed during grain-filling drainage. Accordingly, 2.9–3.3-fold variation in soil Eh and 0.55–0.67-unit variation in soil pH were observed among those sites. In the soil with low moisture, ferrous fractions such as ferrous sulfide (FeS) were prone to be oxidized to ferric fractions; meanwhile, the followed generation of hydroxyl radicals involved in Cd remobilization was enhanced. Consequently, soil dissolved Cd changed from 2.97 to 8.92 μg L−1 among different sampling sites during grain-filling drainage; thus, large variation was observed in grain Cd levels. The findings suggest that grain-filling drainage is the main process controlling spatial variation of grain Cd, which should be paid more attention in paddy Cd evaluation.

Profitability analysis of the use of a variable dosing system for the differentiated application of fertilizer in corn crops

Objective: a profitability comparison was made between corn production with the use of a variable doser and a conventional fertilizer doser. The variable doser for the differentiated application of fertilizer was built at CENEMA of INIFAP. An experimental plot was established, applying the recommendations established in the technological package for grain corn production, by INIFAP, in the State of Mexico.With the variable doser, it was verified that the fertilizer needs of the soil required 11.5 % less than that supplied by a constant application doser. The yield obtained was 5.6 % higher than in the conventional one. The B/C benefit/cost ratio of corn production with the variable doser was 1.60, while with the conventional doser it was 1.44, for both cases the profitability is positive, with a difference of $0.16 cents. The profitability with the use of the variable doser was higher than with the conventional doser.

Edaphic factors mediate the responses of forest soil respiration and its components to nitrogen deposition along an urban-rural gradient

Exploring the influences of nitrogen deposition on soil carbon (C) flux is necessary for predicting C cycling processes; however, few studies have investigated the effects of nitrogen deposition on soil respiration (Rs), autotrophic respiration (Ra) and heterotrophic respiration (Rh) across urban-rural forests. In this study, a 4-year simulated nitrogen deposition experiment was conducted by treating the experimental plots with 0, 50, or 100 kg·ha−1·year−1 of nitrogen to check out the mechanisms of nitrogen deposition on Rs, Ra, and Rh in urban-rural forests. Our finding indicated a positive association between soil temperature and Rs. Soil temperature sensitivity was significantly suppressed in the experimental plots treated with 100 kg·ha−1·year−1 of nitrogen only in terms of the urban forest Rs and Ra and the rural forest Ra. Nitrogen treatment did not significantly increase Rs and had different influencing mechanisms. In urban forests, nitrogen addition contributed to Rh by increasing soil microbial biomass nitrogen and inhibited Ra by increasing soil ammonium‑nitrogen concentration. In suburban forests, the lack of response of Rh under nitrogen addition was due to the combined effects of soil ammonium‑nitrogen and microbial biomass nitrogen; the indirect effects from nitrate‑nitrogen also contributed to a divergent effect on Ra. In rural forests, the soil pH, dissolved organic C, fine root biomass, and microbial biomass C concentration were the main factors mediating Rs and its components. In summary, the current rate of nitrogen deposition is unlikely to result in significant increases in soil C release in urban-rural forests, high nitrogen deposition is beneficial for reducing the temperature sensitivity of Rs in urban forests. The findings grant a groundwork for predicting responses of forest soil C cycling to global change in the context of urban expansion.

Effect of Integrated Use of Manures and Fertilizers on Physico-chemical Properties of Soil and Yield of Coconut (Cocos nucifera L.)

A field experiment was conducted during 2014-15 and 2015-16 in a thirty years old coconut garden of cultivar Pratap to study the effect of Integrated Use of Manures and Fertilizers on Physico-chemical Properties of Soil and Yield of Coconut (Cocos nucifera L.). Accordingly, treatments were applied to coconut orchard in three splits (viz., Stage I- June, Stage II- October and Stage III- February) in a year. Soil samples were collected periodically before fertilizers application and analysed for different physico-chemical properties (viz., pH, EC and organic carbon). The yield of each palm was recorded throughout the year under experimental plot. The application of RDN through FYM at 25 kg/palm/year + Neem Cake at 15 kg/palm/year + Vermicompost at 6 kg/palm/year (T10) recorded significant increase in pH, EC and organic carbon content in soil of coconut orchard. Also the physico-chemical properties of soil found to be improved during second year over the first year of experimentation. The application of RDF + Azadirachtin + Micronutrients through briquettes (T5) received highest yield of coconut. Therefore, it is concluded that application of RDF along with Azadirachtin and Micronutrients through Konkan Annapurna Briquettes in three splits (i.e. June, October and February) is beneficial for increasing the yield of coconut.

The efficiency of different mulch types and dose applications on runoff, soil, and nutrient losses under simulated rainfall

AbstractMulching is one of the best management practices used in soil and water conservation studies. The aim of this study is to determine the effects of different mulch types and doses on runoff coefficient (Rc), soil loss (Er), sediment concentration (Sc), time to ponding (tp), runoff generation time (tr), percolated (pw) and retained (rw) water and total losses of nitrate‐nitrogen (NO3−), ammonium‐nitrogen (NH4+), total nitrogen (TN), phosphate‐phosphorus (PO43−), and total organic carbon (TOC) under simulated rainfall in the laboratory. Three different mulch materials (dry weed, peanut hay, and wheat straw) were applied at four different doses (0, 2, 4, and 6 t/ha) on the experimental plots. A simulated rainfall intensity of 97 mm/s was applied for an hour. All mulch types and doses reduced Rc, and the most effective reduction was found in 2 t/ha dry weed mulch applied plots. The most effective application for reducing soil loss was 6 t/ha peanut hay mulch. The most effective application for delaying the ponding time and runoff generation time was the 4 t/ha application of wheat straw mulch. The highest pw and rw were found in 6 t/ha and 4 t/ha doses of dry weed mulch applications, respectively. The most effective application for reducing NH4+ losses was found in 4 t/ha wheat straw application plots. The most effective mulch type and dose for reducing NO3− loss was 6 t/ha of dry weed mulch. The lowest TN loss was found in the plots where 6 t/ha of peanut hay mulch was applied. In terms of PO43− losses, the lowest loss was in 6 t/ha of dry weed mulch plots. The lowest TOC loss was at 4 t/ha of straw mulch applications. Mulching can be a good natural‐based solution for reducing soil, water, and nutrient loss. However, different mulch types and doses should be tested for different environmental conditions to determine the most cost‐effective mulch type and dose.

Changes in soil bacterial community characteristics in patches of different vegetation types under different stages of restoration in the desert of northern China.

In desert areas, the process of mobile sandy land changing to semi-fixed sandy land and eventually to fixed sandy land after undergoing vegetation restoration is inevitable. The presence of shrub patches and herb patches is common in this restoration process. No relevant studies have reported the soil bacterial community characteristics of different vegetation-type patches (shrub patches and herb patches) under different stages of restoration. Therefore, we utilized long-established experimental plots to collect soil from 0-20 cm soil layer under shrub patches (dominated by Salix psammophila) and herb patches under different stages of restoration (i.e., mobile sand land, semi-fixed sand land, and fixed sand land), by determining soil physicochemical properties, enzyme activities, and soil bacterial communities. Our results found that soil bacterial α-diversity under different restoration stages showed higher shrub patches than herb patches. The dominant bacterial communities (phyla) in shrub patches and herb patches at different recovery stages were Actinobacteria, Proteobacteria, and Bacteroidota. When the mobile sandy land returned to fixed sandy land, the relative abundance of Actinobacteria and Bacteroidota gradually decreased under shrub patches and herb patches, while the relative abundance of Proteobacteria increased significantly. In addition, herb patches significantly increased the relative abundance of bacteria (genus) relative to shrub patches at different stages of recovery. Soil nutrients, soil fine particles, and soil enzyme activities were significantly higher under shrub patches than under herb patches when fixed sandy land due to differences in life form and architecture between shrub patches and herb patches. Based on this, soil bacterial community composition and diversity under shrub patches were driven by more soil properties during the restoration of sandy land. This study complements the dynamic recovery processes and driving mechanisms of soil bacterial community structure under different vegetation patches in sandy areas, especially in the context of global climate change.

Land use modulates resistance of grasslands against future climate and inter-annual climate variability in a large field experiment.

Climate and land-use change are key drivers of global change. Full-factorial field experiments in which both drivers are manipulated are essential to understand and predict their potentially interactive effects on the structure and functioning of grassland ecosystems. Here, we present 8 years of data on grassland dynamics from the Global Change Experimental Facility in Central Germany. On large experimental plots, temperature and seasonal patterns of precipitation are manipulated by superimposing regional climate model projections onto background climate variability. Climate manipulation is factorially crossed with agricultural land-use scenarios, including intensively used meadows and extensively used (i.e., low-intensity) meadows and pastures. Inter-annual variation of background climate during our study years was high, including three of the driest years on record for our region. The effects of this temporal variability far exceeded the effects of the experimentally imposed climate change on plant species diversity and productivity, especially in the intensively used grasslands sown with only a few grass cultivars. These changes in productivity and diversity in response to alterations in climate were due to immigrant species replacing the target forage cultivars. This shift from forage cultivars to immigrant species may impose additional economic costs in terms of a decreasing forage value and the need for more frequent management measures. In contrast, the extensively used grasslands showed weaker responses to both experimentally manipulated future climate and inter-annual climate variability, suggesting that these diverse grasslands are more resistant to climate change than intensively used, species-poor grasslands. We therefore conclude that a lower management intensity of agricultural grasslands, associated with a higher plant diversity, can stabilize primary productivity under climate change.

Ketahanan Varietas Padi terhadap Hama Penggerek Batang (Scirpophaga sp.) di Kampung Telaga Sari Kabupaten Merauke

The rice stem borer (Scirpophaga sp.) is a significant pest of rice plants, causing substantial yield losses. This study aimed to assess the growth response of seven rice varieties to stem borer (Scirpophaga sp.) infestation. The research was conducted in Kampung Telaga Sari, Kurik District, Merauke Regency, from October 2022 to January 2023. The experiment followed a Randomized Complete Block Design (RCBD) with seven varieties and three replications per trial. The varieties tested were Inpari 32, Inpari 42, Cakrabuana, Siam-siam, CL 220, Sertani, and Mekongga. Each treatment was replicated three times, resulting in 21 experimental plots, each measuring 3 x 3 m² with a planting distance of 20 x 20 cm, comprising 50 plants per plot. The research findings indicated significant differences in stem borer damage intensity at the 0.01 level of significance. The highest average attack intensity was observed in the Inpari 32 variety (5.44%), while the lowest average attack intensity was found in the Cakrabuana variety (2%).

Topsoil dilution by subsoil admixture had less impact on soil organic carbon stock development than fertilizer form and erosion state

Enhancing the agroecosystems carbon (C) sink function for climate mitigation faced challenges, particularly with traditional measures with limited suitability for increasing soil organic carbon (SOC) stocks. Inducing a SOC undersaturation in the topsoil by abrupt subsoil admixture is a way to create an additional C sink. However, the deep tillage traditionally used for this topsoil dilution was not always successful. It was due to a lack of knowledge and suitable approaches to record the effect of all relevant factors in SOC recovery, including soil conditions and fertilizer forms.We addressed these problems by establishing a three-factorial experiment: I) “moderate topsoil dilution,” II) “N fertilization form,” and III) “soil erosion state,” representing three soil types in the hummocky ground moraine landscape of NE Germany. SOC dynamics were determined over a year of winter rye cropping using a novel robotic chamber system capable of measuring CO2 exchange on 36 experimental plots with a reduced methodological bias than previous measuring systems.The averaged net ecosystem carbon balance, a proxy for SOC stock change, indicated that topsoil dilution only reduced further SOC losses. The N fertilizer form had a significantly stronger and more differentiated effect. While the mineral N fertilization consistently produced only C sources, the organic fertilization, in combination with the diluted topsoil, led to a C sink. This C-sink function was, however, more pronounced in the eroded soil than in the non-eroded soil. Overall, the results have made clear that the impact of topsoil dilution on the further development of the SOC stock is only possible if the effect of other relevant factors, such as N fertilizer form and erosion state, are taken into account.

Spring sown camelina (Camelina sativa) contributes to the management of three summer weeds

Camelina (Camelina sativa (L.) Crantz) is an attractive drought-tolerant crop for Mediterranean regions due to its rapid growth and ability to out-compete many dicotyledonous winter annual weeds. In this experiment the weed suppression capacity of spring sown camelina against Chenopodium album L. (common lambsquarters), Polygonum aviculare L. (prostrate knotweed), and Xanthium spinosum L. (spiny cocklebur) was studied. The trial was conducted in Lleida (Spain) between 2019 and 2021. Camelina was sown in March each year. Experimental plots contained quadrats with each weed species as well as weed-free and crop-free quadrats. Height and aboveground biomass of weeds in competition with camelina decreased by over 50 % compared to the controls. However, crop and weed growth had seasonal differences depending on the weather conditions: (1) a moderately dry spring promoted crop production (1573 kg ha−1); (2) a rainy spring benefited weed development, negatively affecting crop growth and yield (739 kg ha−1); and (3) a severe dry spring affected growth of both crop and weeds, reducing crop production by up to 80 % (298 kg ha−1). The summer weed suppression capacity of camelina is enhanced by drought conditions, which makes camelina useful for managing these weeds.

Maize plant growth period identification based on MobileNet and design of growth control system

To address the current inefficiencies and subjective nature of manual observation in maize cultivation, with the aim of achieving high efficiency and productivity, this study focused on the DeMaya D3 maize variety. It proposes a maize growth stage recognition method based on the MobileNet model, which is a lightweight convolutional neural network architecture. The method was tested and achieved recognition accuracies of 0.98, 0.96, 0.92, 0.85, and 0.97 for different growth stages, respectively. Additionally, a maize growth prediction model was developed. Based on data collected from experimental plots regarding maize plant height and stem diameter, the Prophet model and an optimized version of the Prophet model were used to forecast maize growth trends. The Prophet model is an open-source tool for time series forecasting. Comparative analysis was conducted between the predictions of the original Prophet model and the optimized version. The relative errors of the Prophet model predictions were 0.85%, 2.11%, and 0.79%, while those of the optimized Prophet model were 0.76%, 0.47%, and 0.71%. Compared to the Prophet model, the optimized model reduced errors by 0.09%, 1.64%, and 0.08%, respectively. The maize plant growth control system was designed to obtain the information through the collection layer. The decision-making layer judged the soil nutrient absorption and growth status. Finally, the management layer controlled water and fertilizer.