Biomass Dry Matter Research Articles

Effects of Phosphorus-Mediated Alleviation of Salt Stress on Cotton Genotypes: Biochemical Responses and Growth Adaptations

Salinity stress can significantly impact productivity in agricultural area with limited water re-sources. Our study focused on how plants under salt stress respond to phosphorus availability in terms of growth and biochemical reactions in cotton genotypes. Two cotton genotypes with different P efficiencies (SK39 and JM21) were used in a hydroponic experiment with 300 mM NaCl and three P treatments (10, 20, and 30 mM). Salinity stress decreases root growth, shoot growth, biomass production, and chlorophyll content, according to the experimental findings. In treated plants, it also increased the levels of oxidative stress. However, this effect was alleviated by phosphorus therapy, which controlled the production of proline, total soluble sugars, and hydrogen peroxide (H2O2). Interestingly, salt-sensitive JM21 responded to phosphorus supplementation more favorably than salt-tolerant SK39. Our research emphasizes the critical role that phosphorus especially P20 plays increasing the salinity stress sensitivity of cotton plants and offers insightful in-formation on the mechanisms underlying the role of phosphorus in reducing salinity stress effects. This study also revealed interspecific variability in cotton genotypes and characteristics, primarily represented by attributes related to cotton growth and morphological indicators such as dry matter biomass.

Livestock turnover and dynamic livestock carrying capacity are crucial factors for alpine grassland management: The Qinghai-Tibetan plateau as a case study

Alpine grasslands are distributed widely on high-elevated ranges and plateaus from the wet tropics to polar regions, accounting for approximately 3% of the world's land area. The Qinghai-Tibetan Plateau (QTP) is the highest and largest plateau in the world, and approximately 60% of the plateau consists of alpine grassland, which is used mainly for grazing animals. Livestock structure was determined in Guinan (GN), Yushu (YS) and Maqu counties (MQ) on the QTP by interviewing 235 local pastoralists. Based on data collected from GN, the livestock carrying capacity was calculated using herbage dry matter biomass intake (LCCm) by the livestock, and the metabolizable energy yield (LCCe) and digestible crude protein (LCCp) available in pasture. The pasture area per household differed among the regions of the QTP, which was the main reason for the difference in livestock stocking rate. The householders raised the appropriate proportion of breeding females and young yaks and sheep in GN and MQ, but not in YS, to maintain a constant turnover. Most pasture in YS was used at the community level, especially in summer. The calculated carrying capacities based on metabolizable energy yield (LCCe) of the pasture and dry matter biomass (LCCm) were similar in most months except for August, when the value of LCCe was higher than LCCm. Based on the digestible protein of the pasture, the calculated livestock carrying capacity overestimated the actual carrying capacity during the herbage growing season from May to September. Appropriate practices should be taken in different regions of QTP, such as providing supplementary feed, especially protein, during the forage non-growing season. Livestock carrying capacity should be adjusted dynamically, and calculated by a number of parameters. The stocking rate should be controlled to optimize livestock production and curb or minimize grassland degradation to generate a sustainable system. This study examined the grasslands and LCC on the QTP, but the results could be applied to grasslands worldwide.

Conservation tillage: a way to improve yield and soil properties and decrease global warming potential in spring wheat agroecosystems.

Climate change is one of the main challenges, and it poses a tough challenge to the agriculture industry globally. Additionally, greenhouse gas (GHG) emissions are the main contributor to climate change; however, croplands are a prominent source of GHG emissions. Yet this complex challenge can be mitigated through climate-smart agricultural practices. Conservation tillage is commonly known to preserve soil and mitigate environmental change by reducing GHG emissions. Nonetheless, there is still a paucity of information on the influences of conservation tillage on wheat yield, soil properties, and GHG flux, particularly in the semi-arid Dingxi belt. Hence, in order to fill this gap, different tillage systems, namely conventional tillage (CT) control, straw incorporation with conventional tillage (CTS), no-tillage (NT), and stubble return with no-tillage (NTS), were laid at Dingxi, Gansu province of China, under a randomized complete block design with three replications to examine their impacts on yield, soil properties, and GHG fluxes. Results depicted that different conservative tillage systems (CTS, NTS, and NT) significantly (p < 0.05) increased the plant height, number of spikes per plant, seed number per meter square, root yield, aboveground biomass yield, thousand-grain weight, grain yield, and dry matter yield compared with CT. Moreover, these conservation tillage systems notably improved the soil properties (soil gravimetric water content, water-filled pore space, water storage, porosity, aggregates, saturated hydraulic conductivity, organic carbon, light fraction organic carbon, carbon storage, microbial biomass carbon, total nitrogen, available nitrogen storage, microbial biomass nitrogen, total phosphorous, available phosphorous, total potassium, available potassium, microbial counts, urease, alkaline phosphatase, invertase, cellulase, and catalase) while decreasing the soil temperature and bulk density over CT. However, CTS, NTS, and NT had non-significant effects on ECe, pH, and stoichiometric properties (C:N ratio, C:P ratio, and N:P ratio). Additionally, conservation-based tillage regimes NTS, NT, and CTS significantly (p < 0.05) reduced the emission and net global warming potential of greenhouse gases (carbon dioxide, methane, and nitrous oxide) by 23.44, 19.57, and 16.54%, respectively, and decreased the greenhouse gas intensity by 23.20, 29.96, and 18.72%, respectively, over CT. We conclude that NTS is the best approach to increasing yield, soil and water conservation, resilience, and mitigation of agroecosystem capacity.

Maize/soybean intercropping increases nutrient uptake, crop yield and modifies soil physio-chemical characteristics and enzymatic activities in the subtropical humid region based in Southwest China

Intercropping, a widely adopted agricultural practice worldwide, aims to increase crop yield, enhance plant nutrient uptake, and optimize the utilization of natural resources, contributing to sustainable farming practices on a global scale. However, the underlying changes in soil physio-chemical characteristics and enzymatic activities, which contribute to crop yield and nutrient uptake in the intercropping systems are largely unknown. Consequently, a two-year (2021–2022) field experiment was conducted on the maize/soybean intercropping practices with/without nitrogen (N) fertilization (i.e., N0; 0 N kg ha−1 and N1; 225 N kg ha−1 for maize and 100 N kg ha−1 for soybean ) to know whether such cropping system can improve the nutrients uptake and crop yields, soil physio-chemical characteristics, and soil enzymes, which ultimately results in enhanced crop yield. The results revealed that maize intercropping treatments (i.e., N0MI and N1MI) had higher crop yield, biomass dry matter, and 1000-grain weight of maize than mono-cropping treatments (i.e., N0MM, and N1MM). Nonetheless, these parameters were optimized in N1MI treatments in both years. For instance, N1MI produced the maximum grain yield (10,105 and 11,705 kg ha−1), biomass dry matter (13,893 and 14,093 kg ha−1), and 1000-grain weight (420 and 449 g) of maize in the year 2021 and 2022, respectively. Conversely, soybean intercropping treatments (i.e., N0SI and N1SI) reduced such yield parameters for soybean. Also, the land equivalent ratio (LER) and land equivalent ratio for N fertilization (LERN) values were always greater than 1, showing the intercropping system’s benefits in terms of yield and improved resource usage. Moreover, maize intercropping treatments (i.e., N0MI and N1MI) and soybean intercropping treatments (i.e., N0SI and N1SI) significantly (p < 0.05) enhanced the nutrient uptake (i.e., N, P, K, Ca, Fe, and Zn) of maize and soybean, however, these nutrients uptakes were more prominent in N1MI and N1SI treatments of maize and soybean, respectively in both years (2021 and 2022) compared with their mono-cropping treatments. Similarly, maize-soybean intercropping treatments (i.e., N0MSI and N1MSI) significantly (p < 0.05) improved the soil-based N, P, K, NH4, NO3, and soil organic matter, but, reduced the soil pH. Such maize-soybean intercropping treatments also improved the soil enzymatic activities such as protease (PT), sucrose (SC), acid phosphatase (AP), urease (UE), and catalase (CT) activities. This indicates that maize-soybean intercropping could potentially contribute to higher and better crop yield, enhanced plant nutrient uptake, improved soil nutrient pool, physio-chemical characteristics, and related soil enzymatic activities. Thus, preferring intercropping to mono-cropping could be a preferable choice for ecologically viable agricultural development.

Application of prohexadione-calcium priming affects Brassica napus L. seedlings by regulating morph-physiological characteristics under salt stress.

Salinity stress imposes severe constraints on plant growth and development. Here, we explored the impacts of prohexadione-calcium (Pro-Ca) on rapeseed growth under salt stress. We designed a randomized block design pot experiment using two rapeseed varieties, 'Huayouza 158R' and 'Huayouza 62'. We conducted six treatments, S0: non-primed + 0 mM NaCl, Pro-Ca+S0: Pro-Ca primed + 0 mM NaCl, S100: non-primed + 100 mM NaCl, Pro-Ca+S100: Pro-Ca primed + 100 mM NaCl, S150: non-primed + 150 mM NaCl, Pro-Ca+S150: Pro-Ca primed + 150 mM NaCl. The morphophysiological characteristics, and osmoregulatory and antioxidant activities were compared for primed and non-primed varieties. Our data analysis showed that salt stress induced morph-physiological traits and significantly reduced the antioxidant enzyme activities in both rapeseed varieties. The Pro-Ca primed treatment significantly improved seedlings, root, and shoot morphological traits and accumulated more dry matter biomass under salt stress. Compared to Huayouza 158R, Huayouza 62 performed better with the Pro-Ca primed treatment. The Pro-Ca primed treatment significantly enhanced chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and actual photochemical quantum efficiency (ФPSII). Furthermore, the Pro-Ca primed treatment also improved ascorbic acid (ASA) content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity, and stimulated the accumulation of soluble proteins. These findings strongly suggested that the Pro-Ca primed treatment may effectively counteract the negative impacts of salinity stress by regulating the morph-physiological and antioxidant traits.

Dry matter production and nutrient extraction by three successive crops fertilized with serpentinite rock as a soil remineralizer

The incorporation of new sources of fertilizers is important to of the food production security. The use of rock powders still needs investigation to address their agronomic efficiency and the safety for the users and for the consumers. This work aimed to study the dry matter production and the nutrient extraction after three consecutive crops, in two soils fertilized with serpentinite rock powder. The experiment was carried in a greenhouse, with three sequential crops, with seven treatments, two soils and four replications. After 40 days of growth, the whole plants were harvested and sent to measure the dry weight and for the chemical analyses. The use of the serpentinite did not increase the total dry matter biomass weight, compared to the fertilized controls. The magnesium extraction was not different between the control treatment with dolomitic limestone and the serpentinite treatment at higher dose for the clayed soil, indicating that the serpentinite was able to supply the magnesium for the plants in the experimental condition, and also a significant dose related effect suggests that the magnesium from the powder has been released. The use of the serpentinite also increased the extraction of other nutrients, like calcium, phosphorus, zinc and iron.

Forage type and additive effects on fermentation quality and biorefinery performance of silages

AbstractThe concept of a green biorefinery has recently gained interest and can be defined as a process where green biomass is processed to a variety of products. Most green biorefineries rely on fresh green biomass as the feedstock, but using a stable ensiled biomass could provide benefits. We evaluated the effects of silage additive treatments on silage fermentation quality and performance in a laboratory scale liquid–solid separation to simulate the first step of a green biorefinery. In Experiment 1, red clover and fresh and wilted grass were ensiled without additive or treated with a lactic acid bacteria inoculant or a formic acid based additive. In Experiment 2, grass or red clover were treated with a fibrolytic enzyme, formic acid or a combination of them, and a control without additive was also included. Silage fermentation quality was improved by additive use. Biomass dry matter concentration was negatively related to liquid yield, but effects of additive treatments on the biorefinery performance were minor and inconsistent between different forages. Optimizing agronomic and feedstock conservation management plays an important role for the success and sustainability of the biorefinery process. Good silage management practices with minimal losses during storage should be targeted, but no clear patterns in biorefinery outputs were observed in the current study when different types of additives were used in grass and clover silage production.

Production and Analysis of Physical, Chemical and Physico-chemical Properties of Biochar from Various Feed Stock Sources

Biochar was derived from a range of biomass materials and its physical and physicochemical characteristics were assessed. Due to the pyrolysis of various biomass products, such as grass, cotton stalks, coconut husk, coconut shell, paddy straw, rice husk, Eichhornia, sugarcane bagasse, and neem wood in the pyrolysis unit. The biochars' characteristics were extremely diverse. Prosopis is superior to other biochars in terms of pore space, pH, EC, CEC, organic C, total N, Mg, available nutrients, and carbon fractions, as evidenced by the large amount of biochar that was recovered from it.&#x0D; Prosopis wood biochar, which can function as a soil enhancer and improve the physical properties of the soil, is superior than cotton stalk biochar and drymatter biomass biochars. It can also increase nutrient availability and retention. Given its higher recovery and diffusion, Prosopis' resource can be used. As a result of the substantial differences between the various biomass, characterizing biochar made from each one is necessary before mass producing it for agricultural application.

Mitigative Effect of Rare Earth Element Cerium on the Growth of Zinc-stressed Wheat （Triticum aestivum L.）Seedlings

This research aimed to clarify the mitigative effect of exogenously applied rare earth element cerium （Ce） on the growth， zinc （Zn） accumulation， and physiological characteristics of wheat （Triticum aestivum L.） seedlings under Zn stress. The wheat variety studied was Bainong307 （BN307）， and Zn stress was achieved by growing seedlings in a hydroponic culture experiment with 500 μmol·L-1 Zn2 + added to the culture solution. It was found that Zn stress at 500 μmol·L-1 significantly inhibited the chlorophyll content， photosynthesis， and biomass accumulation of wheat seedlings. Seedling roots became shorter and thicker， and the lateral roots decreased under Zn stress. The Zn stress also increased MDA accumulation and the degree of cell membrane lipid peroxidation and reduced soluble protein contents and the activities of antioxidant enzymes such as superoxide dismutase （SOD）， catalase （CAT）， and ascorbate peroxidase （APX）. On the contrary， exogenous Ce decreased the adsorption and transport of Zn by the root system and alleviated the damage of Zn stress to wheat seedlings. Specifically， the increase in chlorophyll content （chlorophyll a， chlorophyll b， and total chlorophyll） and photosynthetic parameters， the enhancement of antioxidant enzymes activities and soluble protein levels， and the reduction in MDA content and the damage of lipid peroxidation to the cell membrane were all driven by exogenous Ce， which ultimately led to the increase in dry matter biomass of the root system and shoot. In summary， these results provide basic data for the application of exogenous Ce to alleviate Zn toxicity to plants.

Relationships between combined and individual field crops’ biomass and planting density

ContextField crops, irrigated and rain-fed, constitute the majority of cropland worldwide. An important agricultural variable determining their biomass production is planting density. ObjectiveThe objective of the study was to explore the relationships between the biomass (dry matter) and planting density for either major individual field crops or all field crops, combined, and to suggest empirical models describing them. MethodsThis article describes a meta-analysis of the literature data on biomass per unit area or plant versus planting density for 8 major field crops: 4 cereals (corn, wheat, sorghum, and pearl millet) and 4 forbs (soybean, sunflower, rapeseed, and buckwheat). ResultsWhen data from all 8 field crops are combined, it seems that areal biomass production is practically independent of planting density, apparently obeying the constant final yield hypothesis. By contrast, analyzing each of the 8 crops separately, there is a clear rising trend of areal biomass with increasing planting density, with a mean intraspecific allometric exponent of about 0.25, and individual exponents that increase systematically with a decrease in the average planting density. ConclusionsApplying a planting density-dependent allometric exponent improves the predictability of the interspecific biomass–planting density relationship for field crops. A bounding, exponential model that describes the biomass–planting density relationship in the agricultural range of 1–1000 plants per m2 better than power-law allometric equations is proposed. Although the biological meaning of a derived generic expression relating areal biomass to single-plant biomass for field crops is not clear, the deviation of the outliers probably reflects already utilized or remaining breeding potential for increased areal biomass and agricultural yields. ImplicationsA good understanding, quantification, and prediction of the biomass–planting density relationship is essential for both plant breeding and management of crop production. Plant breeders need this knowledge to choose between strategies for either increasing the single-plant biomass or increasing the plants’ tolerance to high planting density. Agronomists and extensionists need it to optimize planting density for a particular variety under given environmental and agricultural (GxExM) conditions.

Energy yield decline of Sida hermaphrodita harvested for biogas production

The perennial and herbaceous plant Sida hermaphrodita L. Rusby (Sida) has been investigated intensively with respect to its use as a solid biofuel for combustion and, to a lesser extent, for continuous biogas production. Since biogas production provides many opportunities for economic farm diversification, this study compared the biogas potential of Sida with common biogas crops silage maize (Zea mays L.) and cup plant (Silphium perfoliatum L.). To this end biomass samples were collected from a randomized field trial in Southwest Germany during the vegetative stage in five consecutive years starting in 2014. Biogas batchtests revealed constant specific-methane yields of 279 ± 8 LN kgVS−1 for Sida, significantly lower than for maize (335 ± 5 LN kgVS−1) and significantly higher than for cup plant (264.3 ± 3.7 LN kgVS−1). The annual Sida dry matter biomass yields declined significantly by 51% from 2015 (18.2 ± 2.6 Mg ha−1) to 2018 (9.2 ± 4.8 Mg ha−1) as a result of the summer harvest regime. This, in turn, led to a significant decline in Sida's total annual energy yields. Consequently, the average annual Sida energy yield (3549 ± 901 L heating oil equivalents (HOE) ha−1) was significantly lower than for maize (6611 ± 1186 L HOE ha−1) and cup plant (5261 ± 974 L HOE ha−1). These results clearly indicate that harvesting Sida during the vegetative stage for biogas production significantly decreases its energy yield over time. Therefore, Sida can be used economically and ecologically more sustainable for combustion using the dead plant biomass harvested in winter, while cup plant proved competitive to maize for biogas production.

Regulatory effects of Hemin on prevention and rescue of salt stress in rapeseed (Brassica napus L.) seedlings

BackgroundSalt stress severely restricts rapeseed growth and productivity. Hemin can effectively alleviate salt stress in plants. However, the regulatory effect of Hemin on rapeseed in salt stress is unclear. Here, we analyzed the response and remediation mechanism of Hemin application to rapeseed before and after 0.6% (m salt: m soil) NaCl stress. Experiment using two Brassica napus (AACC, 2n = 38) rapeseed varieties Huayouza 158R (moderately salt-tolerant) and Huayouza 62 (strongly salt-tolerant). To explore the best optional ways to improve salt stress resistance in rapeseed.ResultsOur findings revealed that exogenous application of Hemin enhanced morph-physiological traits of rapeseed and significantly attenuate the inhibition of NaCl stress. Compared to Hemin (SH) treatment, Hemin (HS) significantly improved seedlings root length, seedlings height, stem diameter and accumulated more dry matter biomass under NaCl stress. Moreover, Hemin (HS) significantly improved photosynthetic efficiency, activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and decreased electrolyte leakage (EL) and malondialdehyde (MDA) content, thus resulting in the alleviation of oxidative membrane damage. Hemin (HS) showed better performance than Hemin (SH) under NaCl stress.ConclusionHemin could effectively mitigate the adverse impacts of salt stress by regulating the morph-physiological, photosynthetic and antioxidants traits of rapeseed. This study may provide a basis for Hemin to regulate cultivated rapeseed salt tolerance and explore a better way to alleviate salt stress.

Development of machine learning models for estimating wheat biophysical variables using satellite-based vegetation indices

Monitoring wheat biophysical variables during the growing season is essential for achieving precision agriculture's important goals. This study estimated plant height, leaf development stage, leaf area index, dry matter, and plant nitrogen content in wheat from Landsat-7 images in North Iran using machine learning algorithms. Forty points were selected from ten wheat fields (270 ha), and the agronomic parameters were recorded during the 2011–2012 growing season. The machine learning models applied in this study were Artificial Neural Network (ANN), Support Vector Machine (SVM), and Deep Neural Network (DNN). Results suggest that the DNN model was the best for predicting all the parameters, except for the nitrogen percentage, in which SVM and DNN have the same accuracy. The DNN model R2 was 0.82, 0.95, 0.95, and 0.90 RMSE (Root Mean Square Error) 9.61, 0.46, 0.47 and 1.2 and MAE (Mean Absolute Error) 26.4, 0.34, 0.28, and 0.84 for estimating plant height, leaf area index, leaf development stage and dry matter biomass, respectively. The DNN and SVM algorithms can effectively predict plant nitrogen percentage with identical R2, RMSE, and MAE values of 0.83–0.84, 0.44–0.46, and 0.33–0.36, respectively. These results show that machine learning models have great potential to provide timely and accurate data for better wheat management under field conditions from satellite imagery.

Intoxication of newly implanted coffee plants by simulated drift of the dicamba herbicide

After the release of soybean cultivars resistant to the herbicide dicamba, this product should be used more frequently in weed management programs, which may increase the risk of drift to neighboring crops, since the molecules are volatile and might cause damage in non-target plants. This work was developed to evaluate the effects of sub-doses of the herbicide dicamba on young coffee plants, simulating a drift situation. The experiment was carried out in a greenhouse, with a randomized block design of eight treatments and five replications. Each plot consisted of a 4 L pot, filled with sieved clayey soil and tanned manure (3:1 v/v), with a seedling of Catuaí IAC 144 coffee. The treatments used were: 0 (control), 0.0001, 0.001, 0.01, 0.1, 1.0, 10.0, and 100.0 g ha−1 of dicamba. Plant's percentual phytotoxicity was evaluated up to 49 days after application (DAA), SPAD index (14, 28, and 42 DAA), and dry matter biomass, at 49 DAA. In all evaluations, no differences were observed regarding phytotoxicity for dicamba sub-doses of up to 0.01 g ha−1. The highest doses of dicamba caused visual injuries of up to 31%. At 49 DAA, there were no differences regarding dry matter biomass. Leaf symptoms caused by the herbicide were observed, such as curling, wrinkling, and epinasty. No plant death was observed. Compared to other crops, coffee might be considered more tolerant to sub-doses of dicamba, with adequate recovery capacity for reduced doses of this herbicide.

Characterization of Melon, (Cucumis melo L.) Silage with Different Biomass Mixtures and Dry Matter Contents

The objective of this study was to obtain different dry matter contents and proportions of melon plant biomass for silage making. A completely randomized design with factorial arrangement (3 × 2) and four replications was adopted. The first factor consisted of three melon biomass mixtures based on as-fed composition of plant (branches + leaves) and harvested melon (fruits)—100% plant (0% fruit), 90% plant + 10% fruit, and 100% fruit. The second factor corresponded to the ensiled material, which was either fresh or dehydrated in the field after harvest (40% dry matter). Silages produced from dehydrated biomass after fruit harvest, containing 0% and 10% fruit, showed the highest dry matter contents: 297 g/kg and 293 g/kg, respectively. Silages produced from fresh biomass containing 0% and 10% fruit showed high concentrations of acetic acid, reaching 14.9 g/kg and 14.1 g/kg, respectively. Silages produced from dehydrated biomass containing 10% and 100% fruit showed better results in terms of the indicators associated with high-quality silage. Dehydration improves the fermentative profile and overall quality of melon silage.

The Ecophysiological Determinants of Tuber Yield in Response to Potato Genotype and Nitrogen Availability

The cultivar selection and nitrogen (N) fertilization are key management factors to improve potato yield. The aim of the present study was to evaluate the ecophysiological determinants of biomass and tuber yield in potato genotypes in response to N availability under field conditions. Experiments 1 and 2 were carried out in a volcanic soil of southern Chile during the 2021–2022 season. Treatments were applied in the factorial combination of (i) fifteen genotypes of potatoes and (ii) three N fertilization rates (0, 200 and 400 kg N ha−1, 0 N, 200 N and 400 N, respectively). A wide range in total dry matter biomass (5.9–22.1 Mg DM ha−1) and tuber yield (5.1–18.3 Mg DM ha−1) was observed across the experiments. In both experiments, the total biomass and tuber yield were affected by the N rate (p &lt; 0.05) and genotype (p &lt; 0.01), but not by their interaction (p &gt; 0.05). Tuber dry matter yield was strongly related (R2 = 0.94, p &lt; 0.01) to total biomass and weakly related to the harvest index (HI). In both experiments, the total biomass was explained by the radiation use efficiency (RUE) (R2 = 0.69–0.75, p &lt; 0.01). The principal components analysis showed that tuber yield, biomass and RUE were related. The Finlay and Wilkinson analysis revealed that different cultivars varied significantly (p &lt; 0.001) in their sensitivity to N availability. Across environments (3 N rates × 2 experiments), the most responsive cultivars to N availability were Pukara, Rodeo, Asterix and Patagonia. This information will be useful for potato production systems aimed at improving tuber yield and N use efficiency.

Effects of Harvesting Age and Barley Varieties on Morphological Characteristics, Biomass Yield, Chemical Composition, and Economic Benefits under Hydroponic Conditions in Fogera District, Ethiopia

The objectives of this study were to evaluate the effects of harvesting age at 6, 8, 10, and 12 days and four barley varieties HB-1307, Debark-1, Tila, and local varieties on morphological characteristics, biomass yield, chemical composition, and economic benefits under hydroponics in the Fogera district at Fogera National Rice Research and Training Center of Amhara Region, Ethiopia. The interaction effects of harvesting age and barley variety significantly influenced growth parameters of plant height, shoot length, leaf length, and overall chemical composition ( P &lt; 0.05 ). All morphological characteristics were significantly different ( P &lt; 0.01 ) among harvesting ages, and the stem weight, leaf to stem ratio (LSR), and number of leaves per plant were not significantly influenced ( P &gt; 0.05 ) by the different barley varieties. The highest plant height (21.26 cm) and crude protein (CP) content (21.39%) were obtained from Debark-1 at 12 days of harvesting. The highest fresh fodder biomass yield, 203.50 t/ha, and dry matter (DM) yield, 36.21 t/ha, were obtained at 12 days of harvesting. In the case of harvesting age, all morphological parameters increased with the progress harvesting age, except for the LSR and DM content. The highest net return of 2,923,002.25 ETB/ha was obtained from Debark-1 at the 12 days harvesting age, and the lowest 941,201.13 ETB/ha was obtained for the Tila variety at the six days of harvesting age. From the study, it can be concluded that based on fresh fodder biomass yield, DM yield, CP, and economic benefits, Debark-1 was the recommended barley variety on the 12-day harvesting age, followed by HB-1307, local, and Tila barley varieties.

Effects of spring wheat / faba bean mixtures on early crop development

Abstract Aims Intercropping cereals and grain legumes has the potential to increase grain yield in comparison to the respective sole crops, but little is known about mixture effects at the early crop developmental stage. In cereal legume mixtures, the cereal is usually the dominating partner. We aimed to find out when domination starts, which factors may enhance early domination, and if there is a legacy effect of early domination on later growth stages. Methods We set up field trials at a low input conventional site in 2020 and an organic site in 2020 and 2021. Treatments included all possible monocultures and 1:1 mixtures of twelve spring wheat (SW) entries, and two faba bean (FB) cultivars. All combinations were each sown in two sowing densities. To measure the effect of the mixture on early crop development, we counted crop emergence (plant m-2) at ~ 23 days after sowing (DAS) and crop biomass dry matter at ~ 52 and ~ 82 DAS. Results We found positive mixture effects on SW emergence at the conventional site and on SW and FB emergence at the organic site in 2021. Spring wheat was the dominating partner in all three environments; SW domination, without suppressing FB, was already noticed at emergence at the conventional site. There, a small head start of SW at emergence favored dominance at later growth stages and lead to superiority over FB in terms of plant biomass. Conclusions Understanding early dominancy as observed here may help managing competition in mixture to enhance complementarity and improve productivity.

Optimized Nitrogen Fertilizer Rate Can Increase Yield and Nitrogen Use Efficiency for Open-Field Chinese Cabbage in Southwest China

Intensive vegetable production has been characterized by high nitrogen (N) fertilizer input in southwest China. Optimizing the N fertilizer rate is the basis for the optimal management of regional N fertilizer. A two-year field experiment with five N fertilizer rates was conducted during 2019–2021 in southwest China, and the aim of this study was to identify the effects of different N application rates on yield, dry matter biomass (DMB), N uptake, N use efficiency (NUE) and soil mineral N (Nmin) residues for Chinese cabbage (Brassica chinensis L.) and further determine the critical plant N concentration and root-zone soil Nmin residues required to reach the maximum DMB of Chinese cabbage. Five N treatments were established: control without N input (CK); optimal N fertilizer rate decreased by 30% (70% OPT, 175 kg N ha−1), optimized N fertilizer rate (OPT, 250 kg N ha−1), optimal N fertilizer rate increased by 30% (130% OPT, 325 kg N ha−1) and farmers’ N fertilizer practice (FP, 450 kg N ha−1). The N source in all treatments was conventional urea (N ≥ 46.2%). The results showed that the total yield of Chinese cabbage followed a “linear-plateau” trend with an increasing N fertilizer rate. There was no significant difference in yield between the OPT, 130% OPT and FP treatments. The aboveground plant DMB and N uptake showed a ‘slow-fast-slow’ pattern with the growth period. There was no significant difference in aboveground plant DMB and N uptake between the OPT, 130% OPT and FP treatments. Moreover, the OPT treatment significantly increased the aboveground plant DMB and N accumulation by 29.6% and 40.5%, respectively, compared with the 70% OPT treatment. The OPT treatment significantly increased the NUE by 23.8%, 31.2% and 43.1% compared with that in the 70% OPT, 130% OPT and FP treatments, respectively. The linear-plateau model provided the best fit for the relationship among aboveground DMB of Chinese cabbage, plant N concentration and root-zone soil Nmin content. The critical root-zone soil Nmin and plant N concentrations were 94.1, 63.4 and 68.3 kg ha−1 and 34.4, 33.5 and 32.9 g kg−1 during the rosette, heading and harvest periods, respectively. In summary, compared to the FP treatment, the optimized N fertilizer rate (250 kg N ha−1) could significantly reduce the N application rate, maintain yield, increase aboveground plant DMB and N uptake, and improve NUE. Moreover, the study has great significance for guiding the green utilization of vegetable N fertilizer in southwest China.

Efficiency of using growth stimulators and microelements in pea growing technology

Aim. To study the effectiveness of application in a single technological process of fertilization, pre-sowing treatment of seeds with drugs based on an active strain of nodule bacteria, a growth stimulator of biological origin, microfertilizers in a loose form to increase the productivity of peas. Methods. The research program included: phenological observations on the development of plants (phases of development and stages of organogenesis), morphological – on the formation of productivity elements, the leaf apparatus and the duration of its functioning, morphophysiological – on the dynamics of the development of productivity elements, the formation of productive potential. Results. The article presents the results of studies on the effectiveness of growth stimulants and microfertilizers on the formation of pea plants and their yield. The maximum level of realization of the productivity potential of peas was provided by technology projects that provide for the application of mineral fertilizers in doses of N30P45K60 and N15P45K60 + N15 + N15 kg/ha d.r. in top dressing in the «branching» and «budding» phases with the simultaneous application of Maxi-Grow Excel and Tropical products against the background of inoculation of seeds with a strain of nitrogen-fixing bacteria BTU-r, under such growing technologies the yield of pea grain was – 3,74 t/ha, 3,85 t/ha. The authors of the research found that during the period of flowering and formation of beans, the investigated preparations, both of biological and chemical origin, contributed to the formation of higher pea plants with greater biomass, leaf surface and mass of dry matter, compared to the control variant. On average, according to the experiment on options with mineral fertilizer, the use of Maxi-Grow Excel biostimulator increased crop yield by 0.24; 0.22 t/ha; simultaneous application of Maxi-Grow Excel growth biostimulator and Tropicel microfertilizer at 0.58; 0.62 t/ha, the increase from pre-sowing inoculation of BTU seeds with a strain of nitrogen-fixing bacteria was 0,35 t/ha. Conclusions. The maximum productivity indicators were obtained by applying mineral fertilizers in doses of N30P45K60 and N15P45K60 +N15+ N15 kg/ha d.r. in top dressing at III-IV and VIII stages of organogenesis with the simultaneous introduction of Maxi-Grow Excel preparations (in the «branching» and «budding» phases) and Tropicale (in the budding phase) against the background of seed inoculation with a strain of nitrogen-fixing bacteria BTU-r. Under such cultivation technologies, the yield of peas was 3.74 t/ha, 3.85 t/ha, the level of conditional net profit was UAH 13.686–14.016/ha, the profitability was 84%, under favorable weather conditions (2016) – 5.18 t/ha and 5.25 t/ha).