Nutrient Omission Research Articles

Mid-rotation fertilization and liming of Pinus taeda: growth, litter, fine root mass, and elemental composition

Forest floor litter can influence biogeochemical cycling and root growth in Pinus taeda systems, especially on low soil fertility sites. The impact of fertilization and liming on forest floor litter (quantity, elemental composition and root presence) was evaluated in a Pinus taeda stand in southern Brazil. A nutrient omission experiment was initiated in November 2008 on an 11 year-old Pinus taeda plantation. The experiment was a randomized block design with seven treatments and four blocks. The treatments were: complete (macro + micro + lime); minus macronutrients; minus micronutrients; minus K; minus Zn; minus lime; and control. In 2012, forest floor litter samples were collected, divided by layer (new litter, old litter, coarse fragmented forest layer > 2mm, fine fragment forest floor < 2mm, and fine roots) and analyzed for concentrations of Na, Al, and total nutrients. Results indicated that lime increased Ca and Mg concentrations, reduced Al toxicity, and improved fine root growth. An increase in fine roots was observed in treatments without K. There were large increases in Fe and Al as a function of litter age and increased Mn in fragmented litter when lime was applied. There was little variation in forest floor litter accumulation in all treatments. Elemental abundance was C>N>Fe>P>Ca>K>Mg>Mn under control conditions and C>N>Ca>Mg>P>Fe>Mn>K for the complete treatment. Occurrence of needle chlorosis, similar to that reported for Mg, and low growth under lime omission indicate that Mg was a major factor limiting growth. Fertilization and liming affected the bio-cycling of nutrients, Al toxicity, and root growth.

Macronutrient deficiency in cucumber plants: impacts in nutrition, growth and symptoms

This study aimed to assess the growth, nutrition and visual deficiency symptoms of cucumber plants as a function of macronutrient omission. The experiment was conducted in a completely randomized design, with seven treatments and four replicates, corresponding to nutrient solution without nutrient omission (CS) of Hoagland and Arnon, nitrogen (−N), phosphorus (−P), potassium (−K), calcium (−Ca), magnesium (−Mg) and sulfur (−S) omission. Omissions decreased the accumulation of macronutrients with detrimental effects in physiological variables and in the efficiency of absorption, transport and use of macronutrients, causing losses in growth and on dry mass production. Since the losses in dry mass in the shoot were up to 85%, 85%, 83%, 47%, 40% and 40% to the omission of Ca, Mg, N, P, K and S, respectively. The accumulation of macronutrients in the aerial part of cucumber plants that received the complete solution (CS) in relation to each omission (−) was 1058/75, 157/20, 958/152, 578/9, 147/5 and 142/12 for CSN/−NN, SCP/−PP, SCK/−KK, SCCa/−CaCa, SCMg/−MgMg and SCS/−SS, respectively. Therefore, the lowest macronutrients accumulation, the green color index, plant growth and dry matter production were reduced in cucumber plants. The order of limitation of macronutrients in the shoot dry matter production in cucumber plants was N = Ca = Mg > P > K = S.

Adapting the QUEFTS model to predict attainable yields when training data are characterized by imperfect management

Abstract Understanding yield responses to nutrient application is a key input for extension advice and strategic agricultural investments in developing countries. A commonly used model for yield responses to nutrient inputs in tropical smallholder farming systems is QUEFTS (QUantitative Evaluation of the Fertility of Tropical Soils). While QUEFTS has a strong conceptual foundation, a key assumption is that nutrients are the only limiting factors. One implication of this is the required assumption of ‘perfect management’. This may be problematic in the application of QUEFTS in smallholder farming systems with a wide variety of yield limiting factors. In a previous study, QUEFTS was calibrated using farm trials in two major maize production zones in Nigeria. To reduce observed variability in correlations between estimated soil nutrient (N, P, K) supply and soil parameters (e.g. soil organic carbon, soil pH; step 1 of QUEFTS) a Mahalanobis distance method was used to remove data points not adhering to expected correlations. In this study, we assessed an alternative approach: can the QUEFTS model be adapted to fit smallholder farming systems and associated variation in management? Using 676 observations from the same nutrient omission trials in two major maize production zones in Nigeria, we compare a standard linear regression approach with a quantile regression approach to calibrate QUEFTS. We find that under the standard linear regression approach, there is a poor relation between predicted and observed yields. Using quantile regression, however, QUEFTS performed better at predicting attainable yields – defined as the 90th percentile of observed yields – under a wide variety of production conditions. Our results indicate that using quantile regression as a way to predict attainable yields, is a useful alternative implementation of QUEFTS in smallholder farming systems with high variability in management and other characteristics.

Effects of nutrient omission on the reproduction of Meloidogyne javanica in soybean

With the expansion of soybean (Glycine max [L.] Merrill) crop to more sandy soils with lower organic matter (OM) content, the presence of nematodes is one of the main limiting factors for grain yield. The objective of this study was to evaluate the effects of nutrient omission in soybean in relation to the reproduction of Meloidogyne javanica. The experiment was carried out using a completely randomized design in a 2 × 12 factorial arrangement. The treatments were with (+) and without (-) nematode inoculation and nutrient omission (complete, -N, -P, -K, -limestone, -S, -B, -Cu, -Fe, -Mn, -Zn, and control without fertilization), and six replicates. Nematode reproduction (NR), number of nematodes in the roots (NNR), root length (RL), root fresh weight (RFW), shoot fresh weight (SFW), shoot dry weight (SDW), root length, number of pods and flowers, chlorophyll content, and nutritional status of the plant were observed. The reproduction factor and number of nematodes were related to RFW. Apart from RL, in the absence of -N, -limestone, and -S, the presence of the nematode in the substrate caused a reduction in all yield components, and N omission presented the greatest restrictive effect, with reductions of 25.3%, 81.6%, and 84.8% in RFW, SFW, and SDW, respectively, compared to control treatment.

Macroelement omission in hydroponic systems changes plant growth and chemical composition of Melissa officinalis L. essential oil

Macronutrients are essential to several metabolic reactions in plants, as well as to the normal development of vital plant activities. The aim of the current study was to evaluate growth, as well as the content and chemical composition of Melissa officinalis L. essential oil, in plants subjected to mineral omission. The experiment was carried out with Hoagland & Arnon nutrient solution in a hydroponic system, based on the missing element technique. Seven treatments were evaluated: one comprised all nutrients (full treatment) and six missed one nutrient in each solution (-N, -P, -K, -Ca, -Mg, and -S). The increasing order of limiting nutrients for total dry weight was N > K = Ca = P > S = Mg, and that for essential oil content was N > Ca > S = K = P > Mg. Nutrient omission also affected content and chemical composition of its essential oil. Omission of Mg increased chlorophyll, carotenoid and essential oil contents. Thus, it is possible establishing adequate macroelements management to achieve higher growth and content of essential oil.

Insufficient potassium and sulfur supply threaten the productivity of perennial forage grasses in smallholder farms on tropical sandy soils

Perennial forage grass production has the potential to improve smallholder livelihoods in the tropics. However, nutrient management is often challenging, especially on infertile sandy soils. This study tested whether typical nutrient management limits the productivity and sustainability of perennial forage grass systems on sandy soils. Nutrient balances were estimated for four fields of either Megathyrsus maximus cv. Tanzania or Urochloa hybrid Mulato II. Nutrient limitations were then evaluated in a nutrient omission experiment. All soils were sandy (< 10% clay), neutral to acidic (pH (CaCl2) 4.6 to 6.7) and had plant-limiting concentrations of total nitrogen, extractable potassium and extractable sulfur. Nitrogen inputs were typically higher than outputs, with balances ranging from −16 kg ha−1 yr−1 to 293 kg ha−1 yr−1, yet concentrations in forage shoots were low at all sites. Phosphorus balances ranged from −5 kg ha−1 yr−1 to 77 kg ha−1 yr−1 and concentrations in forage shoots were adequate. Potassium inputs were low, resulting in balances from −79 kg ha−1 yr−1 to −138 kg ha−1 yr−1 at locations that did not apply inorganic potassium fertilizer. Potassium concentrations in forage shoots were low and omission of potassium resulted in severely depressed biomass production. Inorganic sulfur fertilizers were not applied to forages and the sulfur balance varied from −1 kg ha−1 yr−1 to −24 kg ha−1 yr−1. Sulfur concentrations in shoots were correspondingly low and production was depressed when sulfur was omitted in the experiment. Balanced nutrition was not achieved, despite substantial fertilizer inputs, resulting in deficiencies of potassium and sulfur, inefficient use of nitrogen and excesses of phosphorus. If current practices continue, potassium and sulfur depletion, phosphorus accumulation and soil acidification can be expected. Recommendations for balanced nutrient management that accounts for high rates of removal in biomass, variable concentrations in organic fertilizers, and leaching potential, are needed to sustain the productivity of perennial forages on tropical sandy soils.

Variability in yield responses, physiological use efficiencies and recovery fractions of fertilizer use in maize in Ethiopia

Physiological use efficiency (PUE), recovery fraction of applied nutrients and indigenous soil nutrient supply form the basis of site-specific fertilizer recommendations. To derive these parameters, and understand their variability, as well as yield responses and fertilizer use profitability, nutrient omission trials (NOTs) were conducted in farmers’ fields across different agro-ecologies in Bako (n = 37), Central Rift Valley (CRV) (n = 66) and Jimma (n = 44) regions of Ethiopia in the main crop growing seasons of 2015 and 2016. The treatments used in the NOTs were control, PK, NK, NP, NPK and NPKSM, where SM refers to secondary and micro nutrients, and applied levels of N, P and K, were 120, 40 and 40 kg /ha, respectively. The results showed that the average yields of the control treatment were 4.5, 3.1 and 2.9 t/ha in Bako, CRV and Jimma, whereas the average yields for the NPK treatment were 8.3, 4.9 and 7.9 t/ha in the respective regions. Nitrogen was limiting grain yield in all the three regions, whereas P limited yield only in CRV and Jimma. The average N agronomic efficiencies in Bako, CRV and Jimma were 25.7, 13.3 and 35.5 kg grain kg−1 of applied N, respectively, under NPK fertilizer use. With the levels of fertilizer used in the NOTs, NK, NP and NPK treatments were profitable in Bako and Jimma, whereas PK was not. None of the fertilizer treatments were profitable in CRV. Soils in Bako and Jimma supplied more N and K but less P than the soils in CRV. The PUE at maximum accumulation, median and maximum dilution of N were 27, 54 and 80 kg grain kg-1 N, while for P, the values were estimated to be 194, 350 and 505 kg grain kg-1 P, and for K they were 16, 52 and 87 kg grain kg−1 K. The estimated average N, P and K recovery fractions were 0.29, 0.05 and 0.06, respectively, in Bako, 0.22, 0.10 and 0.15 in CRV, and 0.38, 0.10 and 0.01 in Jimma. While these average parameter values are relevant, in particular agronomic use efficiencies and recovery fractions showed large variability and, moreover, averages were lower than what is deemed feasible with good agronomy. We discuss the variability in the derived parameters, the relation with yield levels, soil nutrient supply and rainfall, and conclude that caution is needed when deriving fertilizer recommendations from parameters obtained in on-farm experiments. Using single estimated average values is not sufficient: variability in these parameters and sub-optimum values need to be explained first, and derived insight should be used when developing site-specific fertilizer recommendations.

Nutrient management in calcareous soil improves rice–maize sustainable yield index, performance indicators

Rice-maize is an emerging cropping system in South Asia that plays significant role in terms of achieving food security in the region. However, achievement of attainable yield in these two crops is often a constrain due to imbalanced and inadequate use of essential plant nutrients. Understanding the contribution of different nutrients (N, P, K, S and Zn) toward yields of hybrid rice—hybrid maize cropping system in calcareous soil is a need for large number of smallholder farming systems. A four seasons study was conducted with an objective to develop further knowledge on crop productivity and nutrient performance indicators in this newly adapted emerging farming system. Replicated nutrient omission trials were conducted at Bihar, India. At the calcareous soil, omission of the nutrients reduced yields, and N was the most limiting nutrient followed by P and K. Omission of Zn impacted crop yields more than S omission, effect was more prominent in hybrid maize. Nutrient uptake in the cropping system was declined by 58%, 37%, 34%, 31% and 25% for N, P, K, S, and Zn, respectively, when these nutrients were systematically removed from fertilization schedule. Sustainable Yield Index (SYI) for cropping system was highest in the ample balanced fertilizer treatment. Post-harvest soil nutrient availability declined in the nutrient omission plots as compared to the initial soil status. We included additional treatments of ample balanced nutrient application and unfertilized check where hybrid cultivars were replaced by inbred varieties of rice and maize. Cropping system productivity highlighted the synergistic effect of seed and nutrients. The unfertilized checks reduced yield by 9 t/ha and 5 t/ha for the hybrid and inbred cropping systems, respectively. Results from present study conclude that adoption of hybrids in rice-maize system and balanced nutrient management are the best management practices for sustainable food production.

Effect of nutrient omissions on growth, yield, nutrient uptake and economics of potato (Solanum tuberosum L.) in northern Madhya Pradesh

A field experiment was conducted entitled “Effect of nutrient omissions on growth, yield, nutrient uptake and ecomimics of potato (Solanum tuberosum L.) in northern Madhya Pradesh ”at research farm, ICAR-CPRI-RS, Gwalior (M.P.) during the winter season of 2019-20 under the agro-climatic and soil conditions of Northern Madhya Pradesh. The experiment was planted under Randomized Block Design having 11 treatment combinations replicated thrice. Highest growth parameters viz., plant height (56.09 cm), number of stem per plant (5.71) and number of compound leaves/plant (35.08), yield parameters viz. haulm yield (13.75 t/ha), tuber yield (26.67 t/ha) and biological yield (40.42 t/ha) were recorded with 100% recommended dose of NPK. Similarly, chemical parameters viz., N uptake (63.73 kg/ha), P uptake (19.66 kg/ha) K uptake (75.03 kg/ha) in tubers; N uptake (45.39 kg/ha), P uptake (10.3 kg/ha) K uptake (50.6 kg/ha) haulms in 100% RDF NPK treatment. N (176 kg/ha), P (43.37 kg/ha) and K (360.12 kg/ha) contents in soil were highest in T11 (150% Recommended NPK). Highest cost of cultivation (Rs 123200/ha) in 150% RDF NPK but gross return (Rs 366481/ha) was recorded in 100% RDF NPK. However, highest net return (Rs 251681/ha) was recorded in 100% RDF NPK. In contrast to above, highest benefit cost ratio (3.2) was recorded in 100% RDF NPK which was slightly higher to 75% RDF NPK. Thus, resource poor farmers by reducing 25% dose of NPK, can increase return on per rupee invested on one hand and on other hand will contribute environmental safety.

Effect of Nutrient Omission on Grain Yield and Yield Components of Maize (Zea mays L.) at Kersa District, Jimma Zone, Southwestern Ethiopia

Application of fertilizer is the most effective means to increase nutrient uptake in crop plants and improve yields and quality. A field experiment was conducted with an objective to identify which of macronutrients N, P and K are limiting maize grain and yield components in the study area during 2017/18 cropping season. The experiment was laid out in a completely randomized block design with six treatments replicated across six farmers’ fields in Kersa district, Jimma zone, south western Ethiopia. The trial consisted of six treatments, unfertilized control, PK, NK, NP, NPK and NPK+. Maize grain yield was the highest for the NPK treatment followed by NPK+ treatment but lowest for the unfertilized control and N omitted plots. In absence of N, P, and K maize grain yields were significantly lower compared to that of NPK and NPK+ treatments. Among the different treatments, NPK gave the highest grain yield (9185 kg ha^-1), while the control treatment gave the lowest grain yield (1861.3 kg ha^-1). Grain yield levels obtained for different fertilizer treatments were ranked as NPK>NPK+>NP>PK>NK, illustrating that N deficiency was the most yield limiting nutrient followed by P and K in order. Therefore, NPK is the most suitable balanced fertilizers as application of secondary and micronutrients did not further enhance grain yield in the study area.

Can a Combination of UAV-Derived Vegetation Indices with Biophysical Variables Improve Yield Variability Assessment in Smallholder Farms?

The rapid assessment of maize yields in a smallholder farming system is important for understanding its spatial and temporal variability and for timely agronomic decision-support. We assessed the predictability of maize grain yield using unmanned aerial/air vehicle (UAV)-derived vegetation indices (VI) with (out) biophysical variables on smallholder farms. High-resolution imageries were acquired with UAV-borne multispectral sensor at four and eight weeks after sowing (WAS) on 31 farmer managed fields (FMFs) and 12 nearby nutrient omission trials (NOTs) sown with two genotypes (hybrid and open-pollinated maize) across five locations within the core maize region of Nigeria. Acquired multispectral imageries were post-processed into three VIs, normalized difference VI (NDVI), normalized difference red-edge (NDRE), and green-normalized difference VI (GNDVI) while plant height (Ht) and percent canopy cover (CC) were measured within georeferenced plot locations. Result shows that the nutrient status had a significant effect on the grain yield (and variability) in NOTs, with a maximum grain yield of 9.3 t/ha, compared to 5.4 t/ha in FMFs. Generally, there was no relationship between UAV-derived VIs and grain yield at 4WAS (r &lt; 0.02, p &gt; 0.1), but significant correlations were observed at 8WAS (r ≤ 0.3; p &lt; 0.001). Ht was positively correlated with grain yield at 4WAS (r = 0.5, R2 = 0.25, p &lt; 0.001) and more strongly at 8WAS (r = 0.7, R2 = 0.55, p &lt; 0.001), while the relationship between CC and yield was only significant at 8WAS. By accounting for within- and between-field variations in NOTs and FMFs (separately), predictability of grain yield from UAV-derived VIs was generally low (R2 ≤ 0.24); however, the inclusion of ground-measured biophysical variable (mainly Ht) improved the explained yield variability (R2 ≥ 0.62, Root Mean Square Error of Prediction, RMSEP ≤ 0.35) in NOTs but not in FMFs. We conclude that yield prediction with UAV-acquired imageries (before harvest) is more reliable under controlled experimental conditions (NOTs), compared to actual farmer managed fields where various confounding agronomic factors can amplify noise-signal ratio.

Macro- and micro-nutrient uptake pattern and their use efficiencies for maize (Zea mays) in maize-wheat (Triticum aestivum) cropping system under nutrient omissions

A 2-year (2012 and 2013) field experiment was conducted at ICAR-Indian Agricultural Research Institute, New Delhi to assess the effect of omitted nutrients on nutrient concentration and uptake and (nutrient use efficiency) NUE for maize (Zea mays L.) in maize–wheat (Triticum aestivum L.) cropping system. The STCR-based application of nutrients was more rewarding in terms of improved concentrations, uptakes and better NUE of macro (N, P, K) and micro-nutrients (Zn) in maize. This treatment increased the total uptake of N, P and K by 14.9, 12.5 and 9.3 %, respectively, over recommended rates of NPKZn application. The continuous omission of P resulted in 13.7, 11.5 and 4.7 % reduction in total uptake of N, P and K, respectively. Similar to P, omitting K to both crops continuously also resulted in reduction of total uptake of N, P, K, Zn by 22.1, 13.6, 23.4, 1.9, respectively. Omitting Zn to both maize and wheat crop during 2012 and 2013 did not influence total nutrient uptake significantly. Omitting P and K also exhibited reduced agronomic efficiency and apparent recovery. Balanced application of NPK to preceding wheat crop resulted in higher uptake of N, P and K by maize compared to absolute control and imbalanced application of N, NP or NKZn directly to maize crop during experimentation. Omitting N, P or K to maize resulted in reduction in NUE and uptake in maize during second study year.

Productivity and profitability of soybean (Glycine max) as influenced by site-specific nutrient management

A field experiment was conducted during the rainy season of 2018 at CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur to study the effect of site-specific nutrient management on yield attributes, productivity and profitability of soybean. The experiment was laid out in randomized block design comprising of seven treatments (N43P43K50, N43P43K0, N43P0K50, N0P43K50, N20P60K40, FYM@5t/ha and N0P0K0). Experimental site was silty clay loam in texture, acidic in reaction, low in available nitrogen, and medium in available phosphorus and potassium.The highest number of pods (71/plant), seed yield (2 t/ha), net return (45.9×103 `//ha), benefit cost ratio (2.25) and profitability (366.9 `//ha/day) was recorded at N43P43K50. Omission of nutrients significantly reduced productivityand profitability of soybean. The lowest number of pods, seed yield, net return,benefit cost ratio and profitability was recorded in control treatment (N0P0K0). Site specific nutrient management (N43 P43 K50) proved to be the best treatment in enhancing the yield and profitability of soybean.The recommended dose of fertilizers (N20P60K40) and farmer's practice (FYM@5t/ha) proved to be the second and third best treatment, respectively.

Response of Nutrient Omission and Irrigation Scheduling on Growth and Productivity of Maize

An experiment was conducted for response of nutrient omission to irrigation scheduling in hybrid maize during winter season of 2015 at farmer’s field Khajura, Banke where intense summer and severe winter occurs. Soil is sandy loam and climatically humid sub-tropical with average annual rainfall of 1000-1500 mm. The experiment was replicated 3 times with split plot design having plot size of 3 x 3.6 m2. There were three irrigation level as main plot; (30 -35 DAS, tasseling stage), (30-35 DAS, tasseling, grain filling stage), (tasseling stage) and six level of fertilizer dose as sub-plot; farmer fertilization practice (27.6:27.6:18 N-P-K kg ha-1), recommended dose of fertilizer (160:60:40 N-P-K kgha-1), 50 percent above recommended dose (240: 90: 60 N-P-K kg ha-1), N0PK (60:40 P-K kg ha-1), NP0K (160:40 N-K kg ha-1), NPK0 (160:60 N-P kg ha-1). 3 level of irrigation increased the grain yield (4333 kg ha-1) by 33.7% than 2 level of irrigation (3240.6 kg ha-1) and 78.4% than single irrigation (2428.8 kg ha-1). Similarly, 182.4% grain yield could be increased with RDF (4994.9 kg ha-1) than N0PK (1768.6 kg ha-1). Grain nutrient uptake was recorded 80.4% N (56.3 kg ha-1), 79% P (18.8 kg ha-1), 88.8% K (15.1 kg ha-1) higher with three levels of irrigation than single irrigation N (31.2 kg ha-1), P (10.5 kg ha-1), K (8 kg ha-1) and 184% N (64.6 kg ha-1), 183.7% P (21 kg ha-1) and 188% K (17 kg ha-1) was recorded higher with RDF than (N0PK) N (22.7 kg ha-1), P (7.4 kg ha-1), K (5.9 kg ha-1).&#x0D; Int. J. Appl. Sci. Biotechnol. Vol 8(3): 343-354

Camu-Camu: Nutrient Omission Response and Soil Acidity Correction

Camu-camu is an Amazonian fruit that has high levels of vitamin C, however, there is a need to expand knowledge to carry out systematic and consistent studies in the various fields of knowledge, and those related to mineral nutrition. The objective of this work was to evaluate the nutritional and growth status of camu-camu by the missing element technique and the use of liming, using as substratum a dystrophic Yellow Latosol of central Amazonian texture. The experimental design was a randomized block design with four replications and 15 treatments: complete, liming omission, individual omission of N, P, K, Ca, Mg, S, Zn, Mn, Cu, B, Cl and Mo. of the witness (natural soil). The characteristics evaluated were: height, neck diameter, leaf, stem, shoot, root and total dry matter, relative growth, shoot and root ratio, and nutrient accumulation of shoot (leaf) dry matter. All data evaluated were statistically significant. Liming and fertilization were necessary for acidic and low natural soils when comparing the complete with the control. Ca and P were the most limiting nutrients, while omission of N reduced the growth of seedlings. Based on total dry matter, the nutritional requirement of camu-camu was in decreasing order: Ca &amp;gt; P &amp;gt; S &amp;gt; Cl &amp;gt; Cu &amp;gt; Mg &amp;gt; Z &amp;gt; K &amp;gt; Mo &amp;gt; Mn &amp;gt; B &amp;gt; N.

Response of Switchgrass Grown for Forage and Bioethanol to Nitrogen, Phosphorus, and Potassium on Semiarid Marginal Land

A two-year nutrient omission trial was conducted on semiarid wasteland to determine the effects of nitrogen (N), phosphorus (P), and potassium (K) on the chemical composition and theoretical ethanol yield (TEY) of switchgrass (Panicum virgatum L.). The fertilizer treatments were the following: NPK, PK, NK, NP, and no nutrient inputs (CK). Results indicated that the crude protein (CP) content and protein yield of switchgrass aboveground biomass decreased significantly in the PK treatment (N omission) and the CK, compared with the NPK treatment. The omission of N, P, or K did not significantly affect the other feed and energy quality indicators. When averaged across the two years, the neutral- and acid-detergent fiber contents were lower in the NPK and NP treatments, but the CP, dry matter digestibility, dry matter intake, total digestible nutrients, net energy for lactation, and relative feed value were higher, indicating that the suitable application with combination of N and P was helpful to improve the forage quality of switchgrass. In PK and CK treatments, the contents of soluble sugar, cellulose, and hemicellulose were higher but that of ash was lower than that in other three treatments, indicating that no N application meant better quality of switchgrass aboveground biomass for bioethanol production. The TEY at NPK was 2532 L ha−1 in 2015 and 2797 L ha−1 in 2016; in particular, the TEY decreased significantly by 15.1% in PK, 14.7% in NK, 10.5% in NP, and 29.9% in CK in 2016. To conclude, N was the most limiting factor in switchgrass productivity and the combined N, P, and K nutrient supply management strategy is recommended based on the consideration of quality and quantity of switchgrass as forage and bioenergy feedstock on semiarid marginal land.

Mid-rotation fertilization and liming effects on nutrient dynamics of Pinus taeda L. in subtropical Brazil

Since fertilization and liming are unusual practices for managing Pinus taeda L. in Brazil, nutrient exhaustion can occur in the long term. However, recommendations are limited due to lack of studies investigating plant nutrition and nutrient biocycling. Thus, a study was established to investigate the effects of mid-rotation fertilization and liming on foliar, root, and litter nutrient composition. The use of a nutrient omission technique resulted in seven treatments: full (N, P, K, Ca, Mg, B, Zn, Cu, and Mo), -NPK, -micronutrients, -K, -Zn, -lime, and control. Trees were 5 years old when treatments were applied and 12 years old when harvested. At harvest, needle samples from the first and second flushes were collected. Litter layer samples were also collected and divided into four sublayers; the bottom fractions contained roots that were removed and analyzed separately. Fertilizer and lime application increased concentrations of P, K, Ca, Mg, S, Zn, B, and Al in the first and/or second flushes, reduced Mn, and did not change Cu and Fe. Amendment with K resulted in reduced Ca and Mg. Litter layer concentrations of amended elements (Ca, Mg, Cu, Zn, and P) and S were increased, especially in the bottom most fraction. Large accumulations of Ca, Mg, Cu, and Zn were observed in the litter and roots; smaller in K, P, S, B, and Mn were also noted. Degree of litter decomposition led to increased Fe and Al and decreased Mn. Fertilizer and lime application exerted large influences on Pinus nutrition and litter layer chemical quality.

Integrating density and fertilizer management to optimize the accumulation, remobilization, and distribution of biomass and nutrients in summer maize

Improved the utilization of fertilizer while maintaining the increased of grain yield was the focus of Chinese researchers. Nutrient uptake, distribution, and remobilization are important factors affecting the fertilizer utilization and grain yield of maize. This study aimed to provide a theoretical and practical basis for science-based, high-yielding, and high-efficiency cultivation practices by examining differences in biomass and nutrient uptake, distribution, and remobilization characteristics under three cultivation patterns. We set 12 treatments as follows: super high-yielding cultivation pattern (SH), optimized nutrient management cultivation pattern (ONM), local farmer's practice cultivation pattern (FP), and a series of nutrient omission plots, which excluded nitrogen (N), phosphorus (P), or potassium (K) from the three patterns. The results demonstrated that SH and ONM increased the yield and actual harvested ears by 35.4, 20.7 and by 20.2, 17.6%, respectively. Compared with the FP, SH and ONM increased biomass, N, P, and K accumulation at silking (R1 stage) by 24.4, 31.2, 39.4, and 34.8%, and by 21.7, 22.2, 31.7, and 34.8%, respectively. SH and ONM significantly increased biomass and nutrient distribution to the grains. ONM significantly increased N use efficiency. P and K use efficiency under the ONM pattern was significantly higher than under SH, but was lower than under the FP pattern over two years. This research demonstrates that ONM may significantly reduce fertilizer rates, effectively improve the nutrient remobilization efficiency and uptake at post-silking without negatively affecting grain yield, thereby increasing N use efficiency.

Response of crop residue incorporation on Partial factor productivity, recoveries and efficiencies of applied nutrients under maize-wheat cropping system

An experiment was conducted in farm area of Soil Science and Agricultural Chemistry, Birsa Agricultural University, Ranchi, to study the indigenous nutrient supply from nutrient omission plots with and without incorporation of crop residues and their response on partial factor productivity, recoveries and efficiencies of applied nutrients under maize-wheat cropping system. The experiment comprising five treatments with and without crop residues incorporation, replicated four times in a RBD. The results revealed that Partial Factor Productivity of applied N, P & K under maize – wheat cropping system, for SSNM treatment was 37.88 and 35.19, 78.14 and 72.58 & 78.14 and 72.58 kg grain yield per kg N, P and K applied, which was higher than that of NPK treatment (34.57 and 33.01, 60.11 and 57.40 & 62.85 and 60.01 kg grain yield per kg N, P and K applied) with and without incorporation of crop residues, respectively. The agronomic use efficiency of applied N was higher (25.11 - 25.64 kg increase in grain yield per kg applied N) than applied P (24.69 – 27.43 kg increase in grain yield per kg applied P) and followed by applied K (15.77 – 20.34 kg increase in grain yield per kg applied K) in maize-wheat cropping system with and without incorporation of crop residues. With the incorporation of crop residues the nutrient internal use efficiency increased by 3% in wheat but there was not effect of residue incorporation on N internal use efficiency of maize and maize-wheat cropping system. Apparent recovery efficiency of applied N in maize, wheat and maize-wheat cropping system (61.54 – 62.16, 45.97 – 56.87 and 55.64 – 63.15 kg N taken up per kg N applied) was higher than applied P (9.16 – 12.43, 9.58 – 10.45 and 7.83 – 8.57 kg P taken up per kg P applied) and followed by K (84.24 – 89.79, 56.45 – 67.28 and 38.05 – 49.57 kg K taken up per kg K applied).

Site Specific Nutrient Management in Potato Through Nutrient Omission Plot Technique

A field experiment was conducted during four consecutive winter seasons from 2013-14 to 2016-17 at Patna, Bihar under sandy clay loam soil. The trial on potato was laid out in randomized block design with four replications with objective to develop nutrient omission plot technique in potato. The highest plant height and number of shoot per plant were recorded under 150% recommended dose of fertilizer of NPK. The range of dry matter content in potato tuber varied from 16.1 to 17.7% on dry weight basis. The maximum yield of smallest tuber (0-25g) was recorded under 150% recommended dose of fertilizer of NPK, which was at par to all the nutritional treatments and significantly superior over absolute control plot. The maximum yield of medium, large and very large size tuber was recorded under 150% recommended dose of fertilizer of NPK. However, 150% recommended dose of fertilizers of NPK recorded about 13% higher net return over 100% recommended dose of fertilizers of NPK. The maximum yield reduction was observed in the omitted plot without nitrogen among other nutrients like phosphorus and potassium. Hence, nitrogen was one of the most limiting nutrients for tuber yield of potato.