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The growth and productivity of wild lingonberry (Vaccinium vitis-idaea L.) are closely influenced by various environmental factors, including soil composition, climate, light availability, and water levels. This review explores how these conditions and abiotic stress affect lingonberry populations in diverse habitats, from lowland regions to mountainous terrain. Light plays a critical role in flavonoid and anthocyanin synthesis, with solar radiation and photoperiod directly impacting fruit development. Additionally, altitudinal gradients influence the accumulation of polyphenols and vitamin C, while reducing plant height and pollinator activity. Soil types such as cambisols and podzols, often found in subalpine and alpine areas, are favorable for lingonberry growth. Climate factors, particularly winter temperatures and precipitation, significantly affect flowering success, with low temperatures and lack of snow cover negatively impacting fruit production. Forest type and density, including competing vegetation and nutrient availability, further determine the distribution and health of lingonberry populations. This review emphasizes the importance of favorable environmental conditions in promoting the vitality and yield of wild lingonberry, with potential implications for conservation efforts aimed at sustaining its productivity in natural habitats.

Abstract Understanding the efficacy of alternative phosphorus (P) sources in tropical soils is crucial for sustainable farming, addressing resource constraints, mitigating environmental impact, improving crop productivity, and optimizing soil-specific solutions. While the topic holds great importance, current literature falls short in providing thorough, region-specific studies on the effectiveness of alternative P sources in Brazilian tropical soils for maize cultivation. Our aim was to assess the agronomic efficiency of alternative P sources concerning maize crop (Zea mays L.) attributes, including height, shoot dry weight, stem diameter, and nutrient accumulation, across five Brazilian tropical soils. In greenhouse conditions, we carried out a randomized complete block design, investigating two factors (soil type and P sources), evaluating five tropical soils with varying clay contents and three alternative sources of P, as well as a commercial source and a control group. We evaluated maize crop attributes such as height, dry weight biomass, and nutrient accumulation, P availability and agronomic efficiency. Our results showed that, although triple superphosphate (TSP) exhibited greater values than alternative P sources (precipitated phosphorus 1, precipitated phosphorus 2 and reactive phosphate) for maize crop attributes (e.g., height, stem diameter, shoot dry weight and phosphorus, nitrogen, sulfur, calcium and magnesium accumulation). For instance, PP1 source increased nutrient accumulation for phosphorus (P), nitrogen (N), and sulfur (S) by 37.05% and 75.98% (P), 34.39% and 72.07% (N), and 41.94% and 72.69% (S) in comparison to PP2 and RP, respectively. Additionally, PP1 substantially increased P availability in soils with high clay contents 15 days after planting (DAP), showing increases of 61.90%, 99.04%, and 38.09% greater than PP2, RP, and TSP. For Ca and Mg accumulation, the highest values were found in the COxisol2 soil when PP2 was applied, Ca = 44.31% and 69.48%; and Mg = 46.23 and 75.79%, greater than PP1 and RP, respectively. Finally, the highest values for relative agronomic efficiency were observed in COxisol2 when PP1 was applied. The precipitated phosphate sources (PP1 and PP2) exhibited a similar behavior to that of the commercial source (TSP), suggesting their potential use to reduce reliance on TSP fertilization, especially in soils with low clay contents. This study emphasized strategies for soil P management, aimed at assisting farmers in enhancing maize crop productivity while simultaneously addressing the effectiveness of alternative P sources of reduced costs.

Cropland acidification seriously restricts sustainable agricultural development. The main purpose of this study was to determine whether deeper tilling could alleviate topsoil acidification to improve the quality of arable land. A soil column incubation experiment simulating tillage depths (10 cm, 30 cm and 50 cm) and lime addition was conducted to determine their effects on soil acidification improvement. The changes in soil pH, exchangeable acidity, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), available phosphorus (AP), and microbial phospholipid fatty acids (PLFA) were analyzed. Tillage depth, lime application, and their interaction all had significant impacts on soil pH. T50 (simulated tillage depth of 50 cm) and T50+Lime (simulated tillage depth of 50 cm plus lime) treatments significantly increased the topsoil pH from 5.41 to 6.35 and 7.12, respectively. T50 treatment significantly reduced the soil exchangeable acid content compared to the T10 treatment. The nutrient accumulation along soil column indicated that the T50 and T50+Lime treatments significantly increased NO3−-N and AP content in the >30–50 cm soil layer. Compared with T30, NO3−-N accumulation in the >30–50 cm soil layers of T50 and T50+Lime treatments was 6.62 and 7.93 times higher, respectively. The accumulation of AP in the >30–50 cm soil layers of the T50 and T50+Lime treatments was 1.33 and 1.54 times higher than in the T30 treatment, respectively. These findings imply tillage up to 50 cm without exogenous materials could be a potential measure to reduce topsoil acidification and increase nutrition availability of >30–50 cm soil layers. Tillage of up to 30 cm combined with lime application confers greater benefits, which would particularly impact crops with shallow root systems. Subsequent field experiments will be conducted to further investigate the efficacy of these strategies in enhancing crop yield.

Late spring coldness (LSC) is the main limiting factor threatening wheat yield and quality stability. Optimal nutrient management is beneficial in mitigating the harms of LSC by improving wheat root physiology. This study proposed a nutrient management strategy that postponed the application of phosphorus (P) and potassium (K), effectively strengthening wheat’s defense against LSC. This experiment used the winter cultivar “Yannong19” (YN 19) as plant material for two consecutive years (2021–2022 and 2022–2023). Two fertilizer treatments were used: traditional P and K fertilizers application (R1: base fertilizer: jointing fertilizer = 10:0) and postponed P and K fertilizers application (R2: base fertilizer: jointing fertilizer = 5:5); wheat plants at the anther connective formation stage shifted to temperature-controlled phytotrons for normal (T0, 11 °C/4 h) and low temperatures (T1, 4 °C/4 h; T2, −4 °C/4 h) as treatments of LSC. The results showed that under low temperature (LT) treatment, compared with R1, the R2 treatment increased the concentrations of osmotic adjustment substances (soluble sugars and soluble protein contents by 6.2–8.7% and 3.0–8.9%), enhanced activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase activities by 2.2–9.1%, 6.2–9.7% and 4.2–8.4%), balanced the hormone concentrations (increased IAA and GA3 contents by 2.8–17.5% and 10.4–14.1% and decreased ABA contents by 7.2–14.3%), and reduced the toxicity (malondialdehyde, hydrogen peroxide content and O2·− production rate by 5.7–12.4%, 17.7–22.8% and 19.1–19.1%) of the cellular membranes. Furthermore, the wheat root physiology in R2 significantly improved as the root surface area and dry weight increased by 5.0–6.6% and 4.7–6.6%, and P and K accumulation increased by 7.4–11.3% and 12.2–15.4% compared to R1, respectively. Overall, the postponed application of P and K fertilizers enhanced the physiological function of the root system, maintained root morphology, and promoted the accumulation of wheat nutrients under the stress of LSC.

The rice production system in China is facing challenges, including declining soil fertility and a stagnant rice yield. This study aimed to test whether integrating the return of straw to fields with less power puddling could simultaneously enhance soil fertility and rice yields. Therefore, field experiments were conducted in Heilongjiang Province, a key rice-growing region in China, from 2017 to 2021, using three different planting methods: control group (CK), straw return (SR) and straw return integrated with less power puddling (SR + LP). The results showed that small soil aggregates (particle diameter < 0.25 mm) and soil bulk density were significantly decreased when straw return was integrated with less power puddling. These changes contributed to the preservation of soil structure. Simultaneously, this approach significantly increased soil ammonium nitrogen content from 9.9 to 10.9 mg kg−1, organic matter content from 35.0 to 36.2 g kg−1, available nitrogen content from 140.5 to 147.0 mg kg−1 and available potassium content from 128.6 to 136.8 mg kg−1 at mature stage on average. Consequently, the post-heading stored assimilates accumulation of rice was increased from 6.12 to 6.43 t ha−1, and the nitrogen, phosphorus and potassium accumulation of rice were increased by 7.85 kg ha−1, 1.13 kg ha−1 and 5.68 kg ha−1, respectively. These changes ultimately resulted in a higher 1000 g weight and filled grain rate, providing the foundation for higher yields (an increase from 9.31 t ha−1 to 9.55 t ha−1). Furthermore, this approach also increased the net income for farmers by USD 14 t ha−1. In summary, this study demonstrates that integrating straw return with less power puddling can enhance soil’s nutrient supply and retention capacity. This enhancement may boost the absorption and transportation of nutrients, ultimately establishing the groundwork for higher yields and economic benefits by enhancing the 1000 g weight and filled grain rate. Future research should delve deeper into its applicability across different ecosystems and investigate the yield-increasing mechanisms.

IntroductionSoybean breeding in southwestern China has vastly improved soybean yields with the increasing demand for nutrients such as phosphorus (P) and nitrogen (N). This study aimed to assess the impact of soybean breeding on P and N utilization efficiencies.MethodsField experiments with split-plot experimental designs were conducted at two locations [Dafang (DF) and Shiqian (SQ)] in the 2019 growing season to determine the agronomic efficiency of P fertilizer (AEp), P and N utilization efficiencies, and P and N accumulation and partitioning in different soybean organs under 0 (P0) and 35 (P35) kg ha−1 P supply.ResultsThe results showed that soybean breeding targeting high seed yield also improved AEp (p < 0.05) and P (p < 0.05) and N utilization efficiencies (p < 0.05), with the improvement in AEp associated with the high yield response to P supply. P and N accumulation significantly increased in pods (p < 0.05) and leaves (p < 0.05) but not in stems or roots with year of release, while P and N concentrations did not change in any organ with year of release. In addition, only pod dry weight significantly increased (p < 0.01) with year of release, and P and N partitioning increased to pods (p < 0.05) but decreased to stems (p < 0.05) with year of release. Correlation and PCA analyses revealed P and N utilization efficiencies positively correlated with P and N partitioning to pods but negatively correlated with P and N partitioning to stems. While P supply increased P and N accumulation, it reduced P utilization efficiency.DiscussionWe conclude that (1) soybean breeding improved AEp and P and N utilization efficiencies; (2) the increased P and N partitioning to pods but decreased partitioning to stems contributed to the high P and N utilization efficiencies in new soybean cultivars, reducing the demand for N and P; (3) P supply increased nutrient accumulation but reduced P utilization efficiency. These results highlight the significance of appropriate resource allocation among organs and efficient P management for enhancing nutrient utilization and reducing fertilizer requirements.

Abstract The quantification of nutrients accumulated and exported by banana bunches provides information on the crop nutritional requirements. Thus, the aim of this work was to determine the nutritional demand of 'Grande Naine' and 'Prata Comum' banana bunches in the region of Vale do Ribeira, state of São Paulo. Bunch sampling was carried out in six harvest seasons, summer, and winter. The results of dry matter production and nutrient accumulation in bunches were submitted to analysis of variance. Relative growth rates (TCR), organogenic net accumulation (TALON), export and order of nutrient accumulation in bunches were estimated. K and N were the nutrients most accumulated and exported by both cultivars. In har-vest period 5 (commercial harvest), more dry matter was produced in the summer and more nutrients were accumulated in the winter. The highest TCR values were observed between periods 2 and 3 in the summer and between 0 and 1 in the winter, but it did not always follow TALON. The results obtained are important to adapt the nutritional management of these cultivars to the study region, especially in relation to the growing season, due to the longer permanence of the bunch on the plant in the winter and greater demand for nutrients until commercial harvest.

Biochar is frequently utilized as a helpful amendment to sustain agricultural productivity. However, it remains uncertain whether biochar can effectively replace chemical fertilizers, especially in karst regions. To investigate the effects of co-applying biochar and chemical fertilizer on the biological characteristics and fertilizer uptake of pod peppers, as well as to determine the optimal ratio of biochar to chemical fertilizers, a two-year field experiment was conducted in southwest China. The results showed that, compared to the locally typical chemical fertilizer treatment (CF), the combined application of biochar and chemical fertilizer significantly increased the yield of both fresh and dry pod pepper. Chemical fertilizer reduction and biochar application also ameliorated fruit quality, increased nutrient accumulation, and improved fertilizer utilization efficiency. What is more, although the employment of biochar made production costs higher, the reduction in chemical fertilizers and the increase in yield improved economic efficiency, especially in the CF70B treatment (70%CF + biochar). In conclusion, moderate amounts of biochar instead of chemical fertilizers may be a valid nutrient management strategy for pod pepper in the karst mountain areas, which is beneficial for maintaining yield stability, improving quality, and increasing net income.

It was assumed that the production of alfalfa in soils naturally poor in available nutrients, such as potassium (K) and calcium (Ca), depends on the use of fertilizers. This hypothesis was validated in an experiment with an alfalfa–grass mixture carried out in 2012, 2013 and 2014 on soil formed from loamy sand that had a low content of available Ca and K. The two-factor experiment consisted of two levels of applied gypsum as a source of Ca (0, 500 kg ha−1) and five levels of PK fertilizers (absolute control, P60K0, P60K30, P60K60 and P60K120). The total yield of the sward was determined by the main seasons of alfalfa–grass sward use. Gypsum application increased the yield by 1.0 t ha−1. The highest yield of 14.9 t ha−1 was obtained on the plot fertilized with P60K120. Based on the nutrient content in the sward, it was shown that the main yield predictor was the content of K in the first cut of sward use. The reliable yield predictors, based on the total accumulation of nutrients in the sward, turned out to be K, Mg and Fe. The nutritional quality of the alfalfa–grass fodder, based on the K/Ca + Mg ratio, depended mainly on the season of the sward use, which was substantially deteriorated by the K fertilizer. Gypsum did not control this process. The productivity of the nutrients taken up by the sward depended on the accumulated K. Its yield-forming effect was significantly limited by manganese deficiency. The use of gypsum positively affected the uptake of micronutrients, consequently increasing their unit productivity, especially of manganese. Optimization of the production of alfalfa–grass mixtures in soils poor in basic nutrients requires micronutrients to be taken into account. Their uptake by plants can be limited by high doses of basic fertilizers.

The increase in water demand in regions with limited good-quality water resources makes it necessary to study the effect of low-quality water on plant metabolism. Therefore, the objective of this study was to evaluate the effect of water and salt stress on the levels of mineral elements and accumulation of toxic elements Na+ and Cl− in the leaves and their consequences on the production variables of the sorghum cultivar IPA SF-15. The design adopted was randomized blocks in a factorial scheme (4 × 4), with four salt concentrations (1.5; 3.0; 4.5, and 6.0 dS m−1) and four irrigation depths (51.3; 70.6; 90.0, and 118.4% of crop evapotranspiration ETc) in three repetitions. To obtain nutrient, sodium, and chlorine contents in the leaf, we collected the diagnosis leaf from six plants per plot. For production data, we performed two harvests at 76 and 95 days after planting (silage point and for sucrose extraction). We evaluated the dry mass, fresh mass yield, and total dry mass for the two cutting periods and applied the F-test at the 5% significance level. There was an effect of water stress but not saline, making it possible to use saline water for sorghum irrigation. As for the toxicity of ions, the plant showed tolerance behavior to Na+ and Cl− ions. The grain filling phase was more sensitive than the final phase of the crop cycle.

Excessive chemical fertilizer application in greenhouse vegetable cultivation results in environmental risks and residual nutrients in the soil. Conventional plot experiments conducted in one field cannot recommend fertilizer reduction to farmers when the residual nutrient levels were various among different fields. In this study, nine plot experiments were simultaneously conducted in nine greenhouse fields where the soils could reflect different residual levels of nutrient, with two application rates (100 and 0%) for each nitrogen, phosphorus, and potassium fertilizer. The results showed that fertilizer reduction did not decrease vegetable yield when soil nitrate, Olsen–phosphorus, and exchangeable potassium were ≥173.3, 45.8, and 93.1 mg kg−1, respectively. However, no N treatment decreased vegetable yields in fields 1–3 because the inadequately residual nitrate (≤103.9 mg kg−1) in these fields led to low nitrate absorbed from sources other than chemical fertilizer, high recovery efficiencies of N, and high productivity of N absorbed from chemical fertilizer. Residual nitrate that soil EC could reflect was the limiting factor of yield under fertilizer reduction. This study indicated that reducing fertilizer in greenhouse vegetable cultivation should be based on the residual level of nutrients in the soil, which is meaningful in agricultural sustainability and environmental safety.

In the rice–rapeseed rotation system, straw incorporation plays an important role in achieving the rational utilization of resources and maintaining crop production. However, in the study of rice–rapeseed rotation, there was no study on the effect of straw and nitrogen (N) fertilizer in the rice season on the dry matter accumulation (DMA) and nutrient accumulation of subsequent rapeseed. So, this study relied on the localization experiment of rice–rapeseed rotation and annual straw incorporation (full straw returning to the field, SR; the control is full straw removal from the field, CK) with different N fertilizer application rates (N1: 0 kg ha−1, N2: 75 kg ha−1, N3: 150 kg ha−1, and N4: 225 kg ha−1) in the rice season. Based on the fourth year of experiment implementation, the effects of annual straw incorporation combined with the N fertilizer application rate in the rice season on the leaf area index (LAI), photosynthetic potential (PP), DMA and its distribution proportion and rate, and nutrient uptake and its allocation proportion in rapeseed were discussed. At the bolting stage (BS), initial flowering stage (IFS), terminal flowering stage (TFS), and mature stage (MS), the DMA of rapeseed in SR was significantly higher than that in CK by 69.90, 64.27, 62.90, and 41.27%, respectively. The accumulation of N, phosphorus (P), and potassium (K) in SR was significantly higher than that in CK at the BS, IFS, TFS, and MS. Straw treatment had a significant impact on the apparent surplus of N, P, and K in the rice, rapeseed, and annual seasons, while the application of N fertilizer in the rice season had a significant or extremely significant impact on the apparent surplus (AS) of N in the rice, rapeseed, and annual seasons, indicating that fertilization of previous crops had a certain aftereffect. Therefore, straw incorporation is a sustainable farmland management measure.

To determine the optimal row ratio configuration of waxy sorghum-soybean intercropping systems, a field experiment with seven treatments, including sole waxy sorghum (SW), sole soybean (SS), two rows of waxy sorghum alternated with one row of soybean (2W1S), two rows of waxy sorghum alternated with two rows of soybean (2W2S), three rows of waxy sorghum alternated with one row of soybean (3W1S), three rows of waxy sorghum alternated with two rows of soybean (3W2S), and three rows of waxy sorghum alternated with three rows of soybean (3W3S), was conducted during 2019 and 2020 in Guiyang, China. Accumulation and transportation of nitrogen (N), phosphorus (P), and potassium (K) in waxy sorghum were investigated. The results showed that the row ratio configurations had significant effects on the N, P, and K accumulation and transportation of waxy sorghum. On the one hand, compared to SW treatment, intercropping treatments showed higher N, P, and K contents and accumulation amounts, N, P, and K transportation amounts before anthesis, N, P, and K transportation rates before anthesis, and contribution rates of N, P, and K transportation before anthesis to the grain of each organ in waxy sorghum. Similarly, the waxy sorghum-soybean intercropping system increased the yield components (including spike length, grain number per spike, and 1,000-grain weight) of waxy sorghum. In addition, the yields of waxy sorghum and soybean among all treatments were in the sequence of SW (SS) > 2W1S > 3W1S > 3W2S > 3W3S > 2W2S. Besides, the 2W1S treatment showed the highest land equivalent ratio and economic benefit. On the whole, the waxy sorghum-soybean intercropping system can increase the N, P, and K absorption among organs and promote the N, P, and K transportation from vegetative organs to grain in waxy sorghum so as to promote the growth and development of spike in waxy sorghum to obtain higher land equivalent ratio and economic benefits. The 2W1S treatment was recommended as the optimal row ratio configuration of the waxy sorghum-soybean system to achieve the maximum utilization of nutrient resources.

Knowing the accumulation of nutrients in mango plants is essential for calibrating fertilization programs aiming to increase yield in nutritionally unbalanced orchards. The work aimed to evaluate mango nutritional efficiency through nutrient accumulation and partitioning in plants of Palmer cultivar grown in sand soils at São Francisco Valley, Northwest Brazil. Commercial orchards located in Bahia and Pernambuco States, Brazil, under semi-arid climate (BShw; 400-800 mm annual rainfall) had the vegetable biomass and nutrient contents in the mango compartments determined in 1, 2, 4, 7, and 12 years old plants, by evaluating four plants of each age from 20 sample units. The separated samples of the harvested trees originated the compartments roots, stems, thick twigs, thin twigs, leaves and fruits. Nutrient contents and plant dry matter per compartment were determined and plant nutrient accumulation evaluated. Biomass and fruits coefficient of biological utilization were calculated. There was increment in the accumulated content of macronutrients in the mango plants over the years, with superiority for N and K, for which there was a sharp increase as compared to the other macronutrients. Manganese and Fe were the most accumulated micronutrients in the plants over the years. The canopy of the mango Palmer plants is the compartment that accumulates more macro and micronutrients, and the partition within the canopy occurs in the sequence: leaf> thin twig> thick twig. Phosphorus and Mg, and Cu and B are the nutrients more efficient to generate plant biomass and fruit production in the mango Palmer orchards.

Arbuscular mycorrhizal fungi (AMF) colonize the rhizosphere of plants and form a symbiotic association with plants. Mycorrhizal symbionts have diversified ecological roles and functions which are affected by soil conditions. Understanding the effects of different AMF inoculation on plants under varied nutritional conditions is of great significance for further understanding the effects of the external environment regulating mycorrhizal symbiosis on plant phenotypic traits. In this study, the effects of four AMF inoculation treatments on the growth and reproductive performance of cherry tomato (Solanum lycopersicum var. cerasiforme) were investigated under three nutrient levels by pot experiment. It was found that the growth-promoting effect of AMF on cherry tomato decreased with nutrient reduction, and the effects of the same AMF inoculation treatment on cherry tomato were different at different nutrient levels. Nutrient levels and AMF had interactive effects on flower characteristics, fruit yield, resource allocation, and seed germination of the cherry tomato. In addition, AMF could promote sexual reproductive investment. Nutrient levels and AMF also affected the accumulation of nitrogen and phosphorus in cherry tomato, and there were significant differences among different AMF inoculation treatments. The results indicated that nutrient differences could affect the symbiosis between AMF and plants, and confirmed that there were differences in the effects of the four AMF inoculation treatments on the growth and reproductive traits of plants. The differences in growth and reproduction characteristics of cherry tomato between different AMF inoculation treatments at different nutrient levels indicated that the effects of AMF mycorrhizal on the traits of cherry tomato were regulated by nutrients.

Abstract The objective of this work was to quantify the extraction and export of nutrients by common bean (Phaseolus vulgaris) cultivars from different commercial groups and with different growth habits. The experiment was conducted using four common bean cultivars: TAA Gol, BRS FC104, IPR Tuiuiú, and TAA Dama. Total dry matter (DM) and nutrient accumulation in the V4 (with four, six, and eight three-leaflet leaves), R5, R7, R8, and R9 stages was determined, as well as grain yield and nutrient export. Differences were observed both in nutrient uptake and in DM and nutrient accumulation among the cultivars in the initial stages of development (V4 with six and eight three-leaflet leaves). The TAA Gol cultivar showed a greater accumulation of almost all nutrients in these two initial stages. In R7, the cultivar that had the greatest DM and nutrient accumulation was TAA Dama, but, from R8 onwards, there were no significant differences. Although nutrient export is similar among the evaluated cultivars, a lower percentage is translocated to the grain in TAA Dama.

Fertilization programs in lilium are suggested to start after shoot emergence or when the flower buds become visible because the nutrients stored in the bulb are adequate to meet plant demands at the transplant time. Defining plant nutrient uptake is essential to determine the periods of high demand and the amounts at which they should be provided. The objective of this study was to model the nutrients accumulated in Oriental lilium to provide insight into the design of environmentally sound fertilization programs. The most demanded macronutrient was K (1272.8 mg/plant), followed by N (719.1 mg/plant) and Ca (119.7 mg/plant), while Zn (140.7 mg/plant) and Fe (137.7 mg/plant) were the most demanded micronutrients. At the end of the season, most of the Fe (78.0%), P (55.0%) and N (54.3%) originated from the bulb, whereas most of the Ca (86.5%), Mn (84.8%) and Mg (62.9%) were uptaken by roots. During the first 15 days after transplant, 35.1% of the N in the shoot was absorbed from the substrate, as well as 91.0% Mg, 68.6% S, 49.6% K and 13.0% P, suggesting that fertilization for lilium should start at the transplant time. The results suggest that Ca, Fe, Zn and Cu were remobilized from the bulb.

In general, remote sensing studies assessing cover crop growth are species nonspecific, use imagery from satellites or modified unmanned aerial vehicles (UAVs), and rely on multispectral vegetation indexes (VIs). However, using RGB imagery and visible-spectrum VIs from commercial off-the-shelf (COTS) UAVs to assess species specific cover crop growth is limited in the current scientific literature. Thus, this study evaluated RGB imagery and visible-spectrum VIs from COTS UAVs for suitability to estimate concentration (%) and content (kg ha−1) based cereal rye (CR) biomass, carbon (C), nitrogen (N), phosphorus (P), potassium (K), and sulfur (S). UAV surveys were conducted at two fields in Indiana and evaluated five visible-spectrum VIs—Visible Atmospherically Resistant Index (VARI), Green Leaf Index (GLI), Modified Green Red Vegetation Index (MGRVI), Red Green Blue Vegetation Index (RGBVI), and Excess of Greenness (ExG). This study utilized simple linear regression (VI only) and stepwise multiple regression (VI with weather and geographic data) to produce individual models for estimating CR biomass, C, N, P, K, and S concentration and content. The goodness-of-fit statistics were generated using repeated K-fold cross-validation to compare individual model performance. In general, the models developed using simple linear regression were inferior to those developed using the multiple stepwise regression method. Furthermore, for models developed using the multiple stepwise regression method all five VIs performed similarly when estimating concentration-based CR variables; however, when estimating content-based CR variables the models developed with GLI, MGRVI, and RGBVI performed similarly explaining 74–81% of the variation in CR data, and outperformed VARI and ExG. However, on an individual field basis, MGRVI consistently outperformed GLI and RGBVI for all CR characteristics. This study demonstrates the potential to utilize COTS UAVs for estimating in-field CR characteristics; however, the models generated in this study need further development to expand geographic scope and incorporate additional abiotic factors.

Intercropping plays an indispensable role in sustainable agriculture. The response of bandwidth row ratio configuration to crop interspecific relationships and land productivity in the maize–soybean intercropping system (MSI) is still unclear. A 2-year field experiment was conducted with sole maize (SM) and sole soybean (SS), two different bandwidths (2.4 m (B1), 2.8 m (B2)), two different maize and soybean row ratios (2:3 (R1), and 2:4 (R2)) for MSI. The results showed that intercropping had advantages for land productivity compared with sole planting. Intercropping cropping had significant differences on crop yield under different intercropping treatments. The 2-yr average land equivalent ratio (LER, 1.59) and group yield under the intercropping patterns of B1R2 were significantly higher than other intercropping treatments (p < 0.05). With a bandwidth of 2.4 m and planting four rows of intercropped soybean, the total LER and group yield increased by 7.57% and 10.42%, respectively, compared to planting three rows of soybean. Intercropped maize was the dominant species and also had a higher nutrient aggressivity than intercropped soybean. The complementarity effect was higher than the select effect in the MSI system, and intercropping advantage was mainly derived from the complementarity effect, which was significantly correlated with intercropped maize yield. Nitrogen and phosphorus nutrient aggressivity in intercropped maize showed significant correlations with group yield and intercropped maize yield. In conclusion, bandwidth 2.4 m, row ratio 2:4 was a reasonable planting pattern because of its superior land productivity, crop nutrients uptake advantage, and harmonious interspecific relationship, which could provide a reference for MSI promotion and application research.

Camellia oleifera is a woody oil tree with overlapping flower bud differentiation and fruit maturation. Therefore, mechanical harvesting of fruits leads to flower abscission. The present study investigated the effects of flower number per tree on fruit growth, yield, nutrient accumulation, and oil fatty acid composition in C. oleifera. Here, we set different flower numbers per tree by thinning flowers. Heavy flower thinning (T2 and T3) significantly reduced fruit yield and the proportion of palmitic, palmitoleic, linoleic, and linolenic acid in fatty acids compared with other treatments. However, heavy thinning favored an increase in fruit size and weight, seed and dry kernel rate of fresh fruit, soluble protein and oil accumulation in seeds, and the proportion of oleic acid and stearic acid in fatty acids, and it had no significant effect on oil yield per tree compared with light thinning (T1) and control (T0). T2 and T3 decreased soluble sugar content in the kernels at the later stage of fruit development (260–320 days after full bloom (DAFB)) in contrast to the rapid fruit growth period (200–230 DAFB). As the crop load decreased, fruit ABA content increased continuously during 260–320 DAFB, while fruit IAA content increased during 260–300 DAFB and then decreased during 310–320 DAFB. These data suggest that the abscission of a few flowers during mechanical harvesting will not affect fruit production efficiency in C. oleifera.

Lettuce (Lactuca sativa L.), a popular edible vegetable, is highly responsive to mineral fertilizers. A two-year field trial was carried out to determine how nitrogen (N), phosphorous (P), and potassium (K) application ratios affected lettuce growth, yield, and quality. Within a certain range of nutrient application rate, the plant height, stem diameter, yield, and the concentrations of vitamin C and soluble sugar were higher than those without fertilization. Compared with no fertilization condition, the yield increased approximately 13.56–22.03%, 15.15–42.42% and 7.14–10.32% under increased N, P, and K application conditions, respectively. Furthermore, substantial quadratic parabola relationships were observed between lettuce yield and fertilizer application amounts as well as most quality traits. The nitrate concentration was proportional to the N fertilization rate, while the concentrations of soluble sugar and vitamin C positively correlated with N and P application ratios, respectively. The lettuce leaves had the largest N (60.59%) and K (52.25%) accumulations, whereas the lettuce stem had the highest P (46.33%) accumulation. Above all, the optimal N, P, and K application amounts for lettuce were 315 kg N ha−1, 210 kg P2O5 ha−1, and 285 kg K2O ha−1, respectively.

Establishing mixed-species plantations on the reclaimed coastal lands has become a new paradigm in forest management in China, because it increases the provision of ecosystem services. However, the mixing effects of trees with different identities remain largely understudied. In subtropical China, plantations have been historically dominated by monocultures, the conversion of which to mixed plantations are now required considering the need of sustainable forestry development. In this study, we evaluated the soil carbon sequestration, nutrient accumulation, and understory regeneration of three coastal plantations with different compositions established 12 years ago, on a reclaimed area in Eastern China. Plots on two scales (30 m × 20 m for trees and 1 m × 1 m for understory vegetation) were set up to conduct vegetation inventory and soil sampling to compare growth parameters, soil physical and chemical properties, and understory composition. We found that coniferous-mixed forest (CMF) had significantly higher soil available water capacity; both CMF and broadleaved-coniferous mixed forest (B-CMF) had significantly higher soil capillary porosity and soil moisture content at saturation; broadleaved mixed forest (BMF) had a greater soil permeability coefficient. Among soil chemical properties, we observed that CMF had higher soil organic carbon stock and cation exchange capacity in both 0–20 cm and 20–40 cm soil layers. CMF and B-CMF had higher hydrolysable nitrogen and total potassium in both soil layers; BMF had higher available phosphorus contents. Moreover, B-CMF supported better canopy tree growth and higher understory plant species diversity. Therefore, our results showed that the introduction of broad-leaved trees into the coniferous-dominated plantations established on the reclaimed coastal lands produced significant effects on soil properties and understory species diversity. Thus, our study may facilitate the development of new afforestation regimes to mitigate the potential impact of increasing environmental changes by improving our understanding of species composition effects on coastal forest ecosystem functioning.

There are several benefits in the cultivation of Crotalariaspp., including high levels of biomass production and N accumulation, nutrient cycling and antagonistic activity against some nematodes. However, information on nutritional demand is still scarce for these species. This study aimed to determine the dry matter production and macronutrient uptake in shoots of Crotalaria juncea and Crotalaria spectabilis. Two experiments (one for each species) were carried out in a randomized block design, with three replications, assessing thirteen harvest times for C. juncea and ten for C. spectabilis. After each harvest, the samples were dried, weighed and submitted to laboratory analysis, in order to determine the nutrient contents in different parts of the plant. The nutrient accumulation on the shoots, for both species, occurred in the order K > N > P, being the stem the main organ of nutrient accumulation. Also for both species, the export of nutrients by the grains followed the order N > K > P. The maximum dry matter accumulation occurred at 135 and 104 days after emergence (DAE), respectively for C. juncea andC. spectabilis, while the production of viable seeds, in both species, had already begun at 90 DAE.

The knowledge about growth and nutrient accumulation can help improve fertilizer efficiency in the production of jabuticaba seedlings, which is still carried out in an empirical way. This study aimed at determining the growth and macronutrient uptake in ‘Sabará’ jabuticaba genotypes grown in nutrient solution. The experiment was carried out in a completely randomized design in split plots, with four replications. In the main plots three jabuticaba genotypes (J001, J005 and J012) were cultivated in nutrient solution and six evaluation periods (at 60, 120, 180, 240, 300 and 360 days) in the sub-plots were evaluated. Plant height, root length, stem diameter, leaf area index and dry matter (root, stem and leaves) in each period were evaluated. The accumulation of macronutrients in different plant organs was determined, as well as the accumulation of nutrients as a function of time adjusted to the linear model. The results showed that the cultivation in nutrient solution was efficient in the production of Sabará jabuticabeira seedlings. There was no difference in macronutrient growth and absorption among jabuticaba genotypes grown in nutrient solution. ‘Sabará’ jabuticaba plants accumulated (in mg plant-1) 559 of N, 45 of P, 443 of K, 363 of Ca, 59 of Mg and 82 of S. The distribution of macronutrient accumulations in jabuticaba showed the following order: leaves > stem > roots.

The knowledge about growth and nutrient accumulation can help improve fertilizer efficiency in the production of jabuticaba seedlings, which is still carried out in an empirical way. This study aimed at determining the growth and macronutrient uptake in ‘Sabará’ jabuticaba genotypes grown in nutrient solution. The experiment was carried out in a completely randomized design in split plots, with four replications. In the main plots three jabuticaba genotypes (J001, J005 and J012) were cultivated in nutrient solution and six evaluation periods (at 60, 120, 180, 240, 300 and 360 days) in the sub-plots were evaluated. Plant height, root length, stem diameter, leaf area index and dry matter (root, stem and leaves) in each period were evaluated. The accumulation of macronutrients in different plant organs was determined, as well as the accumulation of nutrients as a function of time adjusted to the linear model. The results showed that the cultivation in nutrient solution was efficient in the production of Sabará jabuticabeira seedlings. There was no difference in macronutrient growth and absorption among jabuticaba genotypes grown in nutrient solution. ‘Sabará’ jabuticaba plants accumulated (in mg plant-1) 559 of N, 45 of P, 443 of K, 363 of Ca, 59 of Mg and 82 of S. The distribution of macronutrient accumulations in jabuticaba showed the following order: leaves > stem > roots.

Cereal–legume mixtures are often associated with higher yields than the components grown as sole crops, but the underlying mechanisms are unclear. The study aims to evaluate how different cultivars in a two-species wheat–faba bean mixture influence above- and below-ground nitrogen (N) accumulation in the plant biomass, whether crop mixing affected the accumulation of other nutrients relative to the accumulation of N and phosphorus (P), and how the nutrient accumulation pattern in sole crops and mixtures is influenced by weed competition. Using a growth container experiment, we investigate nutrient accumulation patterns on specific wheat and faba bean cultivars grown as sole crops and mixtures, and with and without weed competition. We found that cereals in the mixture accumulated more N than in the sole crops, and the cultivar used influenced biomass accumulation in the legumes. Competition from weeds reduced the amount of plant N pools accumulated in the crop plant biomass. Based on stoichiometric scaling exponents, the plant neighbor affected the accumulation of other nutrients relative to the accumulation of N and P. These results are relevant for species and cultivar selection, all of which are important prerequisites for maximizing mixture performance.

Soil aggregates are the material basis of soil structure and important carriers of nutrients. Long-term application of organic and inorganic fertilizers can affect the composition of soil aggregates to varying degrees, which in turn affects the distribution and storage of soil nutrients. We report the results of a 15-year long-term field-based test of aeolian sandy soil and used the wet sieve method to analyze the stability of water-stable aggregates, as well as the distribution characteristics of nutrients in different particle size aggregates. Our results show that long-term application of organic fertilizer (M3) and combined organic–inorganic treatments (NPK1-M1, NPK1-M2, and NPK1-M3) help to increase the amount of organic carbon, inorganic carbon, and cation exchange in the macro-aggregates, and the improvement rates are 92–103%, 8–28%, and 74–85%, respectively. The organic content of the fertilizers also promotes the formation of macro-aggregates, and the stability of aggregates increase from 0.24 to 0.45. In contrast, the application of inorganic fertilizers (NPK1, NPK2, and NPK3) has no marked effect on the formation and stability of macro-aggregates; the application of inorganic fertilizers can merely maintain the organic carbon content of the soil. Correlation analysis shows that the application of organic fertilizers and chemical (inorganic) fertilizers containing phosphorus and potassium can markedly increase the content and reserves of available phosphorus and potassium across all aggregate sizes, and there is a significant positive correlation between these parameters and the amount of applied fertilizer (p < 0.05). Aggregates of various sizes in aeolian sandy soils in arid areas have the potential for greater nutrient storage. Therefore, organic fertilizers can be used in the agricultural production process to improve soil structure and fertility.

Transplanting kohlrabi (Brassica oleracea var. gongylodes), a cool-season vegetable crop, in early spring may provide the opportunity for double cropping in short-season regions such as the Northeastern United States. A two-year field study evaluated the impacts of transplanting dates on yield and nutrient concentration of kohlrabi. Additionally, this study aimed to quantify the nutritional value of kohlrabi leaves. The yield of kohlrabi increased by as much as 307 kg ha−1 for each day transplanting was delayed. Soil temperature increased by 2.8 °C between April 23 and May 14, resulting in the increased accumulation of Ca, Cu, Mn, and Fe in kohlrabi bulbs and Ca and Cu in leaves. The nutrient concentration in leaf and bulb were positively correlated, indicating that the two commodities can be simultaneously harvested for optimum quality. Leaf yield was not significantly different among transplanting dates. However, the number of leaves and total leaf area increased with delayed transplanting. Leaf yield and leaf area were not correlated with bulb yield, suggesting that the reductions in yield and nutrient concentrations were unrelated to photosynthetic efficiency. Although the earlier transplanting of kohlrabi may have provided opportunities for double cropping, the yield and nutrient accumulation of kohlrabi transplanted early in the spring were considerably compromised.

Phytoremediation is an effective and ecological method used to control soil secondary salinization in greenhouses. However, the plant–soil interactions for phytoremediation have not been studied sufficiently. In this study, three crop species (Astragalus sinicus (CM), Spinacea oleracea (SP) and Lolium perenne (RY)) were compared in a greenhouse experiment. The results showed that all three crops increased the soil microbial biomass, the abundance of beneficial microorganisms, available phosphorus and soil pH, and reduced the soil salt content. The crop nutrient accumulation was positively correlated with the relative abundance of bacterial 16S rRNA sequences in the soil. CM and RY respectively increased the relative abundances of norank_f_Gemmatimonadaceae and norank_f_Anaerolineaceae within the soil bacterial community, while SP increased the relative abundances of Gibellulopsis within the fungal community. Correlation analysis revealed that pH and total dissolved salts were the vital factors affecting soil microbial communities in the secondary salinized soil. Our results suggest that phytoremediation could effectively alleviate secondary salinization by regulating the balance of soil microbial community composition and promoting crop nutrient accumulation.

Abstract: The objective of this work was to evaluate the concentrations and accumulation of macronutrients in conilon coffee (Coffea canephora) fruit, and their concentrations in leaves, over two years, in irrigated and nonirrigated coffee plants. Three-year-old conilon coffee plants of the cultivar Emcapa 8111 genotype 02 were used. An experimental design was carried out in randomized complete blocks, in a split-plot arrangement, with 14 replicates. The main plot factor was irrigation versus nonirrigation of coffee plants, and the split-plot factor was different fruit and leaf collection times. Collections began 10 days after the beginning of flowering and were performed on average every 28 days, until full fruit ripening. At each sampling date, five plants per treatment were picked out, by collecting one plagiotropic branch by plant, separated into fruit and leaves. Each part was dried, weighed, and subjected to the chemical analysis. Macronutrient accumulations and their accumulation rates were determined. According to the regression analysis of the data, fruit macronutrient accumulation curves fit best to sigmoidal equations. Irrigation affects the macronutrient dynamics in fruit and leaves during the fruiting phase of conilon coffee, and increases the accumulation of nutrients in the plant tissues. The macronutrients found in greater quantities are N, K, and Ca, in fruit and leaves, regardless of the irrigation treatment.

Plant-available nutrients in soils are usually distributed in a heterogeneous or patchy manner. Plant responses to low levels of phosphorous (P) are not uniform across and within species. In this study, we examined the adaptive role of physiological plasticity (increased rate of nutrient uptake in localized zones) to the heterogeneous distribution of P in the soil, and whether low P stress transcends to the shoot and triggers similar biochemical changes that enhance tolerance. Two Chinese fir clones with high P efficiency (M1, which is tolerant to low P, and M4 which is able to decouple fixed P) were chosen as the research materials and their physiological responses to low P stress were examined using a sand culture experiment. For both clones, there was no significant difference in nutrient concentration between P-replete and P-deficient patches. Heterogeneous P supply did not affect the allocation of nutrients to the above-ground parts of the plants. The activity of acid phosphatase (APase) and malondialdehyde (MDA) content increased initially but declined with increasing duration of stress, while the content of soluble protein and total chlorophyll contents remained unaffected by the heterogeneous P supply. We conclude that physiological plasticity plays no role in adaptation to low P stress in these clones, while the changes in APase activity and MDA content in needles suggest functional metabolic processes are involved in enhancing P-efficiency in these clones.

Objective Swine manure in Korea is separated into solid and liquid phases which are composted separately and then applied on land. The nutrient accumulation in soil has been a big issue in Korea but the basic investigation about nutrient input on arable land has not been achieved in detail. Within the nutrient production from livestock at the national level, most values are calculated by multiplication of the number of animals with the excreta unit per animal. However, the actual amount of nutrients from swine manure may be totally different with the nutrients applied to soil since livestock breeding systems are not the same with each country. Methods This study investigated 15 farms producing solid compost and 14 farms producing liquid compost. Composting for solid phase used the Turning+Aeration (TA) or Turning (T) only methods, while liquid phase aeration composting was achieved by continuous (CA), intermittent (IA), or no aeration (NA). Three scenarios were constructed for investigating solid compost: i) farm investigation, ii) reference study, and iii) theoretical P changes (ΔP = 0), whereas an experiment for water evaporation was conducted for analyzing liquid compost. Results In farm investigation, weight loss rates of 62% and 63% were obtained for TA and T, respectively, while evaporation rates for liquid compost were 8.75, 7.27, and 5.14 L/m2·d for CA, IA, and NA, respectively. Farm investigation provided with the combined nutrient load (solid+liquid) of VS, N, and P of 117.6, 7.2, and 2.7 kg/head·yr. Nutrient load calculated from farm investigation is about two times higher than the calculated with reference documents. Conclusion The nutrient loading coefficients from one swine (solid+liquid) were (volatile solids, 0.79; nitrogen, 0.53; phosphorus, 0.71) with nutrient loss of 21%, 47%, and 29%, respectively. The nutrient count from livestock manure using the excretion unit has probably been overestimated without consideration of the nutrient loss.

This study is to find out an appropriate log cutting period for saprotropic Lentinula edodes log cultivation. Seasonal changes in nutrients in sapwood and cell activities in the inner bark from logs of Quercus acutissima cut during September to February were analyzed. Total carbon content in the sapwood was higher in September (76.5%) than in other months (67.8–69.2%). Total nitrogen content was higher in November and December (0.21–0.22%) than in other months (0.14–0.15%). Inorganic nutrients such as phosphate, potassium and magnesium, and heavy metals like cadmium were higher in November and December than in other months. Over 90% of axially vertical and radial parenchymatous cells contained starch granules in November and December while only 20–30% of these cells did in February. The cell activities in the inner bark of logs cut in October to November, measured with formazan absorbance values during mid March, were 0.013–0.018, which were lower than those cut in December (0.027–0.045). Therefore, our results support that it is better to cut logs for L. edodes cultivation in November when nutrients accumulate in the wood but wood cells are less active.

The key objective of winter oilseed rape cultivation, resulting from its broad spectrum of uses, is to harvest maximum yield of oil. It has been formulated a hypothesis, which assumed that mineral composition of seeds allows a reliable prediction of both crude oil concentration (COC), and yield of oil (YOI). This concept has been validated in three 2007/08, 2008/09, 2009/10 seasons. The field experimental design was composed of six fertilizing treatments: absolute control (AC), NP, NPK, NPKMgS1 (1/3 total MgS rate applied in spring), NPKMgS2, (total MgS rate applied in autumn), NPKMgS3 (2/3 - autumn, 1/3 - spring). The COC depended on both factors, but any interactional effect was found. The YOI was a result of interaction of both factors, reaching the highest value of 2.6 t*ha-1 in 2008 in the plot fertilized with NPKMgS2. The COC was a result of positive impact of calcium and negative by both nitrogen, and magnesium. The YOI was the best predicted by calcium concentration. It has been found that any calcium concentration increase above 3.0 g*kg-1 DM resulted in decrease of the crude oil yield. The prediction of both oil characteristics was more reliable based on nutrient accumulation in seeds. As again magnesium was the key predictor of COC, exerting a negative impact on this characteristic. The optimum set of YOI predictors was depended on the group of treatments. In all considered treatments, the YOI was affected by the interactional effect of phosphorus (negative), and potassium (positive). In the set of treatments, composed of NPK and its variants with MgS rates, the YOI was depended on the amount nitrogen and zinc in seeds. The first nutrient affected positively and the second negatively the yield of crude oil.

Abstract: The objective of this work was to evaluate the nutrition, accumulation of nutrients in residual straw, pure seed yield, and seed quality of the tropical forage grasses 'Mombaça' and 'Xaraés' subjected to topdressing with nitrogen fertilizer management. Field experiments were carried out in the municipalities of Rancharia and Presidente Prudente, in the state of São Paulo, Brazil. The treatments included a control (without N topdressing) and four N fractionation forms at different forage stages: 150 kg ha-1 N, at the vegetative phase (VP); 150 kg ha-1 N, at the beginning of the reproductive phase (RP), between panicle initiation and the prebooting stages; 100 kg ha-1 N, at VP plus 50 kg ha-1 N at RP; and 50 kg ha-1 N at VP plus 100 kg ha-1 N at RP. Fertilization with N as topdressing, regardless of the N fractionation form, increased N concentration in the flag leaf and in residual straw, and the quantities of N accumulated by 'Mombaça' and 'Xaraés' forage grasses. The application of all or most N in the VP increased the quantities of residual straw and of P and K accumulated by the 'Mombaça' forage grasses. The application of all or most N in the RP provided a greater pure seed yield and N use efficiency in both forage grasses. The seed physiological quality of the forages is not affected by fertilization with N topdressing.

Root plasticity is important for plants to adapt to heterogeneous nutrient environments. The differential responses of six spring wheat genotypes were investigated; the plants had been subjected to deficient (2 μmol) and abundant phosphorus (P) (200 μmol) concentration. Root (length, surface area and diameter) and root hair traits (length and density), soil acidification and uptake of macro- and micronutrients were determined. Under low P supply all genotypes exhibited symptoms of P stress, such as poor shoot and root growth, starch accumulation and a release of substantial quantities of proton and acid from roots. Larger genotypic differences in root hair length and density than root length, surface area and diameter were observed. In response to P stress genotype April Bearded responded strongly by increasing its root hair density, while A35-213 and Hankkijan Tapio substantially increased root hair length. Other genotypes showed less positive responses or even negative ones in root hair traits. Thus, density of root hairs appears to be a more P-regulated and P-responsive trait than root hair length. April Bearded acidified the most and Hindy62 released most organic acid in response to P deficiency.

New shoots (including newly formed leaves and twigs) and fruits of citrus tree are key organs for present yield formation and flower differentiation in the next season, but the relationship between yield fluctuation and accumulations of major nutrients in new shoots and fruits of citrus tree is still unclear. Thus, to quantify the biomass and mineral nutrient accumulation in new shoots and fruits of citrus trees under varied yield levels has essential significance for rational fertilization and pruning management for citrus orchards. The purpose of this study was, therefore, to investigate the accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), and the distribution of biomass in new shoots and fruits of citrus trees under low, medium and high-yield levels in each of eight orchards located in Chongqing, China. The results showed that substantial variation of fruit yield was observed in all eight orchards with an average yield of 15.0 (low), 30.9 (medium) and 60.1 (high) kg/plant. The averaged biomass of new shoots ranged from 1.59 to 2.51 kg/plant, which was significantly and positively correlated with fruit yield. Nutrient accumulation in leaves was generally highest among new organs, while more than half of N (52.70–71.4%), P (66.5–80.4%) and K (68.9–85.9%) accumulated in fruit. Fruit yields closely correlated with total amounts of major nutrients in new shoots. Furthermore, the nutrient requirements per unit of newly developed shoots and fruits were gradually decreased with increased yield, but the removed nutrients per ton of fresh fruit were almost stable, indicating that more nutrients were distributed into fruit tissues. Taken together, these findings are valuable for optimizing nutrient and pruning management in citrus orchards in China and other similar countries.

ABSTRACT: Determining nutrient uptake and accumulation rates by cotton crops is important to define management strategies, especially for transgenic varieties, which are cultivated using high-technology approaches that require substantial investment to maximize yield. Currently in Brazil, the states of Bahia and Mato Grosso are responsible for 84.4 % of the total cotton growing area. In the present study, two trials were conducted in 2013, one that involved planting FM 940 GLT, FM 980 GLT, and FM 913 GLT varieties in the state of Bahia and the other which involved FM 940 GLT and FM 980 GLT varieties in the state of Mato Grosso. The aim of the two trials was to represent the two regions that currently encompass the largest areas of cotton cultivation. Tissue samples, consisting of leaves, stems, and reproductive components, were collected eleven times during the crop cycle for determination of nutrient content and shoot dry matter. After weighing, plant tissue samples were dried and ground to determine nutrient contents. Because there were no overall differences in nutrient contents and biomass accumulation of the varieties during the crop cycle, we undertook joint analysis of the data from all varieties at each site. Favorable climatic conditions in Bahia promoted plant biomass production that was twice as much as plants grown in Mato Grosso, with cotton yields of 6.2 and 3.8 t ha−1 of lint and seed, respectively. The maximum nutrient accumulation occurred between 137-150 days after emergence (DAE) for N; 143-148 for P; 172-185 for K; 100 for Ca; 144-149 for Mg; and 153-158 for S. Maximum uptake ranged from 218-362 kg ha−1 N; 26-53 kg ha−1 P; 233-506 kg ha−1 K; 91-202 kg ha−1 Ca; 28-44 kg ha−1 Mg; and 19-61 kg ha−1 S. On average, the sites revealed nutrient export of 14, 2, 23, 3, 2, and 2 kg t−1 of lint and seed for N, P, K, Ca, Mg, and S, respectively, with little variation among sites. Extraction of nutrients per area by cotton vary among sites, but nutritional requirement of cotton per unit of lint and seeds is similar independently of yield potential.

A four-year field experiment was conducted to investigate the effect of subsoiling depth on root morphology, nitrogen (N), phosphorus (P), and potassium (K) uptake, and grain yield of spring maize. The results indicated that subsoil tillage promoted root development, increased nutrient accumulation, and increased yield. Compared with conventional soil management (CK), root length, root surface area, and root dry weight at 0–80 cm soil depth under subsoil tillage to 30 cm (T1) and subsoil tillage to 50 cm (T2) were significantly increased, especially the proportions of roots in deeper soil. Root length, surface area, and dry weight differed significantly among three treatments in the order of T2 > T1 > CK at the 12-leaf and early filling stages. The range of variation of root diameter in different soil layers in T2 treatment was the smallest, suggesting that roots were more likely to grow downwards with deeper subsoil tillage in soil. The accumulation of N, P, and K in subsoil tillage treatment was significantly increased, but the proportions of kernel and straw were different. In a comparison of T1 with T2, the grain accumulated more N and P, while K accumulation in kernel and straw varied in different years. Grain yield and biomass were increased by 12.8% and 14.6% on average in subsoil tillage treatments compared to conventional soil treatment. Although no significant differences between different subsoil tillage depths were observed for nutrient accumulation and grain yield, lodging resistance of plants was significantly improved in subsoil tillage to 50 cm, a characteristic that favors a high and stable yield under extreme environments.

The aim of this study was to investigate the variation in concentration of macro- and micro- nutrients in soil and shoots of Quercus castaneifolia seedlings growing in flooded and non-flooded conditions. For this purpose, one-year old seedlings of this species were subjected for 120 days to three different conditions: (i) well-drained control (ii) permanent flooding and (iii) periodic flooding in an experiment as a completely randomized design. The results showed that flooding reduced the ratio of Organic carbon, Total Nitrogen and available Potassium in the soil. Potassium concentration in permanent flooding was reduced to 49% in comparison to control treatment. Also, in the permanent flooding, availability of Fe and Mn increased to 42% and 51% with respect to controls, respectively. Under flooding conditions, nutrient accumulation decreased in leaves of stressed seedlings. In addition, the reduction in N, Ca and Mg in permanently flooded seedlings was greater than those in seedlings growing under periodic flooding. The Zn concentration in leaves diminished as a result of the permanent flooding. In both flooding regimes, Mn concentration in leaves with respect to controls increased 2.5 times, whereas Fe concentration increased 2.5 and 3.5 times, respectively. There was found a positive significant correlation between most of nutrient concentrations of soil and leaf. In conclusion, macro-nutrients in soil and shoot of seedlings under flooding stress were reduced whereas micro-nutrients increased. Taking into account that some macro-nutrient concentrations in soil and leaf of seedlings grown in periodic flooding were greater than those in permanent flooding, it is concluded that for growth of Q. castaneifolia seedlings, periodic flooding is more favorable environment than permanent flooding.

A literatura brasileira apresenta poucos dados para subsidiar a recomendação de adubação para a cultura do caquizeiro, portanto o objetivo deste trabalho foi estudar o acúmulo de massa seca e macronutrientes nos órgãos que compõem o ramo produtivo, ao longo dos estádios fenológicos da cultura de caqui cultivar Giombo e quantificar as necessidades de nutrientes para a produção. O estudo foi realizado em pomar localizado no município de Faxinal-PR, e as amostragens de ramos frutíferos foram iniciadas três semanas após o início da brotação, repetidas a cada três semanas, durante 45 semanas. Foram realizadas análises químicas dos materiais coletados e determinada a extração de nutrientes ao longo do estádio de desenvolvimento. O total de macronutrientes exportados pela colheita dos frutos foram: 25,47; 5.72; 51.53; 6.76; 2.79 e 5,09, respectivamente, para N, P, K, Ca, Mg e S em kg por ha, para produtividade de 27.7 toneladas por ha de fruto, e os exportados pela retirada de ramos podados para fora do pomar, por questões fitossanitárias, foram: 2,1; 0,3; 1,1; 5,8; 0,5 e 0,4 kg de N, P, K, Ca, Mg e S em kg por ha.There is no information supporting fertilization for persimmon crop as far as the Brazilian literature is concerned. Therefore, the goal of this paper was to study the accumulation of dry mass and micronutrient in organs that compounds the productive branch, during phenological growth stages of persimmon cv. Giombo, and to quantify the nutrient requirement for production. The study was carried out in an orchard located in Faxinal-PR. The spacing between plants was 6 x 7 meters. The sampling of fruiting branches started three weeks after budding had begun and this procedure was repeated after every three weeks during 45 weeks. Chemical analyses of the samples were performed and nutrients extractions during phenological growth stages were determinate. The total of macronutrients removed by fruit harvest was 25.47; 5.72; 51.53; 6.76; 2.79 and 5.09 kg per hectare, respectively for N, P, K, Ca, Mg and S. The nutrient extraction by pruning branches for phytosanitary control was 2.1; 0.3; 1.1; 5.8; 0.5 and 0.4 kg per hectare of N, P, K, Ca, Mg and S. The productivity was 27.7 ton of fruits per hectare.

ABSTRACT Upland rice cultivars manifest different nutritional demands. A field study was conducted to quantify the extraction, distribution, and removal of micronutrients and silicon by the upland rice cultivars. The experiment was arranged in a randomized complete block-split plot design. Plots consisted of three cultivars (Caiapó – traditional, BRS Primavera – intermediate, and Maravilha – modern) of upland rice. Split-plots consisted of plant samplings, which occurred at 39, 46, 55, 67, 75, 83, 92, 102, 111, 118, and 125 days after emergence (DAE). Up to the end of tillering (46 DAE), all cultivars exhibited low demand for most micronutrients and Si, and took up less than 24 % of the total B, Cu, and Si, but around 31 % of the total Zn. The period of greatest uptake of micronutrients and Si occurred from 65 to 80 DAE in the Caiapó and BRS Primavera cultivars, and after 80 DAE in the Maravilha cultivar. The Caiapó and BRS Primavera cultivars took up their necessary demand of B, Mn, and Fe in the first 98 DAE and Cu, Zn, and Si up to 105 DAE, but the Maravilha cultivar took up these nutrients for two to three weeks longer. The quantities of micronutrients and Si taken up by cultivars Caiapó, BRS Primavera, and Maravilha did not exhibit large differences, and these cultivars took up between 98-135 g B, 103-110 g Cu, 1,157-1,460 g Fe, 1,278-1,424 g Mn, 240-285 g Zn, and 111-124 kg Si per hectare. The BRS Primavera cultivar showed greater removal of nutrients, with average amounts per hectare of 19.7 g B, 25.8 g Cu, 200 g Fe, 234.2 g Mn, 102.4 g Zn, and 32.6 kg Si, while the other cultivars removed smaller amounts per hectare (14.4 g B, 19.9 g Cu, 160.7 g Fe, 136.3 g Mn, 67 g Zn, and 21.9 kg Si). The BRS Primavera showed a greater removal of nutrients because it has a higher yield and allocates a greater quantity of nutrients to the panicles.

Foi conduzido experimento de campo em Mauá da Serra, Estado do Paraná,para avaliar a produção de matéria seca e o acúmulo de nutrientes pelas culturas de aveia branca (Avena sativa), trigo (Triticum sativum), aveia preta (Avena strigosa L.) com 40 kg ha-1 denitrogênio, aveia preta sem aplicação de nitrogênio e a vegetação espontânea no tratamento em pousio. Em sucessão, avaliou-se a cultura da soja (Glycine max) em um Latossolo Vermelho distroférrico sob semeadura direta, há 23 anos. Os resultados indicaram que a aveia preta com adubação nitrogenada produziu a maior quantidade de matéria seca, seguida pela aveia preta sem adubação nitrogenada, aveia branca, trigo e vegetação espontânea. A aveia preta com e sem adubação nitrogenada foi superior no acúmulo de nitrogênio, fósforo,potássio, cálcio, magnésio, zinco, cobre e manganês. A maior produtividade da soja foi constatada em sucessão a aveia preta com adubação nitrogenada, em média 0,88 mg ha-1 de grãos, em relação aos demais tratamentos.A field experiment was carried out in Maua da Serra, State of Paraná to evaluate the production of dry matter and nutrient accumulation ofwhite oat (Avena sativa), wheat (Triticum sativum) and black oat (Avena strigosa) with 40 kg ha-1 of nitrogen, black oat without nitrogen addition and the population of spontaneous plants on treatments in fallow. In succession, a soybean (Glycine max) culture was grown in a Haplorthox, in no tillage for 23 years. Results showed the black oat with fertilization nitrogen addition produced the greatest quantity of dry matter, followed by the black oat without fertilization nitrogen addition, white oat, wheat and the natural vegetation. The black oat with and without fertilization nitrogen showed the best results on the nitrogen, phosphorus, potassium, calcium, magnesium, zinc, copper and manganese accumulation. The soybean yield was greater in succession of the black oat with N fertilization, an average of 0.88 mg ha-1 grains, in relation to the other treatments.

O experimento foi conduzido com o objetivo de determinar a concentração e acumulação de N, P e K no feijoeiro (cv. BR Ipagro 1 "macanudo") cultivado sob diferentes níveis de irrigação: Sem irrigação (SI); irrigação ao ser atingida a tensão matricial de 80kPa (I-80kPa) e; a 40 kPa (I-40kPa). Os resultados obtidos no florescimento indicam que a concentração de N (3,72%) não variou em relação aos níveis de irrigação utilizados. Para o P, diferiu entre o SI (0,23%) e os irrigados (0,30%). Para o K, diferiu entre o SI (0,73%) e o l-40kPa (1,16%). Na maturação fisiológica, a concentração de N nos grãos variou e apresentou média de 3,47%. Entretanto, para P (0,54%) e K (0,89%) não variou. As quantidades totais de N, P e K acumuladas diferiram entre o tratamento SI e os tratamentos irrigados e apresentaram médias de 62,4 e I23,8kg de N/ha, 8 e 18,8kg de P/ha e 23,7 e 50,7kg de K/ha, respectivamente, para SI e irrigados.This study was carried out with the objective to determine NPK concentration and accumulation of black beans (Phaseolus vulgaris L., BR Ipagro 1 "macanudo" varie ty) cultivated under different sprinkling irrigation levels. The three irrigation levels were: without irrigation (Wl), irrigation when matric potential reached 80kPa (I-80kPa) and 40kPa (I-40kPa). The results of the flowering sampling indicated that the N concentration (3.72%) was not affected by irrigation levels. Leaf concentration of P in the leaves were different between WI (0.23%) and the irrigated treatments (0.30%). In the maturity stage the N grains concentration changed with irrigation and presented average values of 3.47%. However. P (0.54%) and K (0.89%) grains concentrations were similar. The whole amount of NPK accumulated was different for WI and irrigated treatments. The average values of 62.4 and 123.8kg of N/ha, 8 and 18.8kg of P/ha and 23.7 and 50.7kg of K/ha, were observed for WI and irrigated treatments, respectively.

ABSTRACT Studies in the past decades have focused on how tuber yield of potato grown on different types of soil is affected by phosphate fertilizer rates. However, little is known about the effects of phosphorus availability in the soil and of phosphate fertilization on nutrient uptake and removal by the main potato cultivars currently grown in Brazil. Thus, in this study we investigated the influence of P fertilization rates on dry matter (DM) yield and nutrient uptake and removal in five potato cultivars grown on soils with different levels of P availability. Experiments were conducted on soil with low (14 mg dm-3), medium (36 mg dm-3), and high (70 mg dm-3) P availability, in randomized complete blocks with a 5 × 5 factorial arrangement with four replications. The treatments consisted of five potato cultivars (Agata, Asterix, Atlantic, Markies, and Mondial) and five P rates (0, 125, 250, 500, and 1,000 kg ha-1 P2O5) applied in the planting furrow. In soils with low, medium, and high P availability, P fertilization increased plant growth and tuber DM yield up to rates of 500, 250, and 125 kg ha-1 P2O5, respectively. At a specific initial P availability, all potato cultivars responded to the same P rate for plant growth, tuber yield, and nutrient uptake and removal. At the highest P fertilization rates, leaf analysis showed that the nutritional status of potato plants was not significantly changed and no nutritional deficiency was induced, regardless of the soil P availability levels. However, in the soils with higher P availability, P fertilization decreased plant Mn and Zn and tuber Mn concentrations in a linear manner. The increases in the uptake of N, K, Ca, Mg, S, B, Cu, and Fe and the removal of most nutrients in response to P fertilization were related more to the increase in plant biomass and tuber DM yield than to changes in concentrations of these nutrients in the plant. Application of P at high rates in soil with high P availability caused luxury P uptake, which reduced Mn uptake by 10 % and prevented higher Zn uptake, by reducing plant Zn concentrations, despite the increase in plant biomass.