Nutrient Harvest Index Research Articles

Nutrient uptake, partitioning, and removal in two modern high-yielding Colombian rice genotypes

The objective of this research was to determine the difference on growth between a rice cultivar with Clearfield® technology (Only Rice 228) and a hybrid (Benja 1); to characterize nutrient uptake, distribution, accumulation and removal between these two commercial genotypes. Tests under shade house and field conditions were performed to estimate macro and micronutrient uptake patterns. Plants were sampled at nine growth stages (emergence, initiation of tillering, active tillering, initiation of panicle primordia, booting, flowering, milky, soft dough and mature grain) and divided into different organs for nutrient determination. The results showed that “Benja 1” plants (92 d) had a shorter cycle than “Only Rice 228” (OR 228) plants (118 d). “OR 228” exhibited a greater biomass production (16.575 kg ha−1 vs. 12.621 kg ha−1) in field. The nutrient acquisition was faster in the hybrid Benja 1 between tillering initiation and the milky grain stage in which the N, K, Ca, Mg, Mn, B, and Cu uptake was more evenly and highly distributed throughout these stages in both conditions. “Benja 1” showed a higher nutrient harvest index (HI). HI values above 50% (P (62%), N (61%), Cu (67%), S (55%), and Mg (52%)) were found in Benja 1 under field conditions. The results also highlight Si removal in both rice genotypes, in which Benja 1 stands out. These results provide information on the nutrient uptake and partitioning of modern rice genotypes, and give the knowledge to optimize fertilizer programs and timing recommendations for rice biomass and grain production in Colombia.

Nitrogen, phosphorus and potassium accumulation and partitioning by the potato group Andigenum in Colombia

Accumulation curves for nitrogen (Naccum), phosphorus (Paccum), and potassium (Kaccum) obtained from total dry biomass (W) can be employed for the prognosis of potato production in the Andean region, along with analysis of nutrient partitioning derived from the nutrient harvest index (NHI, PHI, KHI). This research established accumulation curves and translocation curves for N, P, and K using allometric relationships in the potato cultivars Diacol Capiro and Pastusa Suprema (Solanum tuberosum, group Andigenum), cultivated in soils with high and low fertility. The best fit of the accumulation model was obtained with the low fertility soils for the ‘Supremaʼ (Naccum = 68.13W0.504, Paccum = 6.724W0.779, and Kaccum = 63.93W0.776), which expressed the highest production potential and high values of NHI (0.55–0.69), PHI (0.75–0.8) and KHI (0.62). The ‘Capiro’ was better adapted to the changes in soil fertility than the ‘Supremaʼ since the models for nutrient accumulation in the ‘Capiro’ were significant for both levels of soil fertility. The efficiency of N, P, and K translocation into tubers followed a positive logarithmic model, which showed differences in favor of the ‘Capiro’ in the translocation efficiency of mineral nutrients. The accumulation of N, P, and K was established per cultivar and per phenological stage of growth, with up to 33% more P extracted by tubers in the ‘Capiro’ than in the ‘Supremaʼ and a comparable extraction of N and K by tubers in both cultivars.

Conventional Harvest Index Methods may Overestimate Biomass and Nutrient Removal from Abscising Crop Species

ABSTRACT Harvest index (HI) is conventionally measured using end-of-season biomass, but leaf abscission during crop growth can represent a substantial portion of total crop biomass for several species. A field study was conducted in Florida, USA, to determine the accuracy of conventional and alternative HI methods using sesame (Sesamum indicum L.) as a model species and to assess biomass and nutrient contributions from abscised leaves. Seed and nutrient HI was determined from three cultivars using the following four methods: (1) total biomass method that included both end-of-season and seasonal abscised biomass; (2) conventional method based solely on end-of-season biomass; (3) early-bloom method in which biomass collected during early-bloom stage was used as the nonseed biomass component; (4) mid-bloom method where biomass from mid-bloom stage was used for nonseed biomass. Early- and mid-bloom methods overestimated all HI and underestimated biomass and nutrient return to the soil. Most nutrient HI based on the conventional method was higher than the values based on the total biomass method. Compared to the total biomass method, the conventional method underestimated biomass and nutrient return to soil per ha by 714.8 kg biomass, 28.5 kg nitrogen, 3.6 kg phosphorus, 34.7 potassium, 4.6 magnesium, 25.7 calcium, 3.4 kg sulfur, 26.5 g boron, 361 g zinc, 25.9 g manganese, 527.2 g iron, and 18.7 g copper. Including abscised leaves when determining HI may not be feasible in field experiments due to labor constraints but is an option when measuring HI for species under similar management at regional scales to improve estimates of nutrient cycling.

Effect of elevated [CO2 ] on yield, intra-plant nutrient dynamics, and grain quality of rice cultivars in eastern India.

Climate models predict an increase in global temperature in response to a doubling of atmospheric [CO2 ]. This may affect future rice production and quality. In this study, the effect of elevated [CO2 ] on yield, nutrient acquisition and utilization, and grain quality of rice genotypes was investigated in the subtropical climate of eastern India (Kharagpur). Three environments (open field, ambient, and elevated [CO2 ]) were tested using four rice cultivars of eastern India. Under elevated [CO2 ] (25% higher), the yield of high-yielding cultivars (HYCs) viz IR 36, Swarna, and Swarna sub1 was significantly reduced (by 11-13%), whereas the yield increased (by 6-9%) for Badshabhog, a low-yielding aromatic cultivar. Elevated [CO2 ] significantly enhanced K uptake (by 14-21%), but did not influence the uptake of total N and P. The nutrient harvest index and use efficiency values in HYCs were reduced under elevated [CO2 ] indicating that nutrient translocation from source to sink (grain) was significantly reduced. An increase in alkali spreading value (10%) and reduction in grain protein (2-3%) and iron (5-6%) was also observed upon [CO2 ] elevation. The study highlights the importance of nutrient management (increasing N rate for HYCs) and selective breeding of tolerant cultivars in minimizing the adverse effects of elevated [CO2 ] on rice yield and quality. © 2018 Society of Chemical Industry.

Nutrient uptake of iron, zinc, magnesium, and copper in transgenic maize (Zea mays) as affected by rotation systems and N application rates

Understanding the interaction of macro- and micronutrients is a prerequisite to targeting nutrient balance in crop production. A 3-year field study was conducted to determine mineral nutrient uptake of maize hybrids with N fertilizer application under different rotation systems. The experiment was arranged in a split-plot design with rotation [maize-alfalfa (MA), maize-soybean (MS), and continuous maize (MM)] by N rate (0, 50, 100 and 150 kg N ha−1) as the mainplot and hybrid as the subplot. Two additional treatments (200 and 250 kg N ha−1) were tested in MM. Maize plant total Mg, Zn, and Cu content were in the order: MA > MS > MM. Plant Fe uptake was the lowest in MA and not affected by N input. The increased Cu uptake with increasing N rates indicated the synergism of these two nutrients, whereas dilution effects of N application on stover Zn and Mg concentrations were recorded. Rotation systems and N rates interactively affected nutrient harvest index and internal efficiency of Zn, Mg, Fe, and Cu. Relationships of plant N with Cu and Mg concentrations, and N with Zn, Mg, and Cu content at the V6 stage were established, but they were not necessarily preserved at maturity due to the progressive synergistic and dilution effects. The findings of nutrient uptake of Cu, Zn, Mg and Fe and their relationships with N nutrition in maize with stacked transgenic traits are important for developing best management practices to achieve concurrent improvements in nutrient use efficiency and crop productivity.

Productivity, Seed Quality and Nutrient Use Efficiency of Wheat (Triticum aestivum)under Organic, Inorganic and Integrated Nutrient Management Practices after Twenty Years of Fertilization

A long-term field experiment started in 1995 on Research Farm of Department of Soil Science, CCS Haryana Agricultural University Hisar (India) was selected to study the effects of organic manures and chemical fertilizers on productivity, seed quality and nutrient use efficiency of wheat under pearl millet-wheat cropping system. The organic manures (15 Mg FYM, 5 Mg poultry manure and 7.5 Mg pressmud) were applied alone and in combination with fertilizers (150 kg N + 30 kg P2O5 ha−1) and compared with chemical fertilizers applied alone (150 kg N + 60 kg P2O5 ha−1 and 75 kg N + 30 kg P2O5 ha−1). The results showed that the application of organic manures in combination with N and P fertilizers significantly increased all yield attributes, i.e. plant height, number of tillers/m row length, spike length, number of grains/spike. Higher grain yield of wheat (61.4, 57.4 and 62.7 q ha−1) was observed when recommended dose of N and half of P was applied in conjunction with FYM, poultry manure and pressmud, respectively. Grain yield of wheat increased by 13.5, 6.1 and 15.9%, respectively, under same treatments when compared with recommended dose of N and P fertilizers. Among the organic manures, highest yield (32.9 q ha−1) was obtained with pressmud application. However, application of organic manures alone resulted in poor yield and even lower than 50% recommended dose of N and P fertilizer. All the seed quality parameters (standard germination, shoot length, root length, seedling dry weight, seedling vigour index-I and -II) improved with the combined application of organic manures and chemical fertilizers as compared to their individual application. The partial factor productivity of N and P increased with combined application organic manures and chemical fertilizer as compared to chemical fertilizers applied alone, however, nutrient harvest index and their utilization efficiency decreased with combined application of organic manures and fertilizers as compared to their individual application.

Effects of Fertilizer Levels on the Absorption, Translocation, and Distribution of Phosphorus and Potassium in Rice Cultivars with Different Nitrogen-Use Efficiencies

<p>The fertilizer management and the selection of rice cultivars play a vital role in rice production to maximize yield and minimize fertilizer cost. Many researches have elucidated the combined increase of nitrogen (N) accumulation and N use efficiency (NUE) in different rice genotypes, however, the accumulation, translocation, distribution of phosphorus (P) and potassium (K), and the correlation of N, P and K absorption characteristics and their relationships with grain yield in rice cultivars with different NUE is still obscure. For this purpose, two rice cultivars differing in NUE were chosen for this study, one with high-NUE (Dexiang 4103) and the other with low-NUE (Yixiang 3724). Fertilizers were applied at three levels, including low (75 kg N·hm<sup>-2</sup>, 37.5 kg P<sub>2</sub>O<sub>5</sub>·hm<sup>-2</sup>, 75 kg K<sub>2</sub>O·hm<sup>-2</sup>), medium (150 kg N·hm<sup>-2</sup>, 75 kg P<sub>2</sub>O<sub>5</sub>·hm<sup>-2</sup>, 150 kg K<sub>2</sub>O·hm<sup>-2</sup>), high rate (225 kg N·hm<sup>-2</sup>, 112.5 kg P<sub>2</sub>O<sub>5</sub>·hm<sup>-2</sup>, 225 kg K<sub>2</sub>O·hm<sup>-2</sup>). A no-N treatment was included for each level as the control. The results showed that there were obvious interacting effects of cultivars and fertilizer levels on grain yield, as well as the absorption and translocation of P and K. Rice cultivars exhibited markedly stronger effects on total spikelets and the translocation of P and K in leaves, compared to fertilizer levels. The opposite trend was observed for grain yield, P and K accumulation at the main growth stages, and P and K translocation in stem and leaf sheaths. Compared with other treatments, the combined application of NPK fertilizers at medium level promoted nutrient accumulation, increased the nutrient harvest index, facilitated nutrient translocation in vegetative organs, and ultimately improved grain yield in both cultivars. The equilibrium relationship between N, P and K accumulation and grain yield indicated that the grain yield associated with high-NUE cultivar could reach more than 10,000 kg hm<sup>-2</sup>, with N, P, and K requirements of 180.8-213.3, 47.3-54.7, and 223.5-259.1 kg hm<sup>-2</sup>, respectively. Additionally, the correlation analysis revealed that accumulation and translocation of P, K during different growth stages was significantly (P < 0.05) related to grain yield and nutrient accumulation in different NUE cultivars. This study suggested that varieties with high-NUE also has high P and K use efficiencies, indicating that the conventional screening of varieties with high P or K use efficiencies can be included in the selection of high-NUE varieties. The increase of P and K accumulation and translocation during the period from heading to maturity was helpful to maintain a high-yield and NUE in rice production.</p>

NUTRIENT RECOMMENDATION MODEL FOR CARROT CROP – FERTICALC CARROT

ABSTRACT The literature on fertilization for carrot growing usually recommends nutrient application rates for yield expectations lower than the yields currently obtained. Moreover, the recommendation only considers the results of soil chemical analysis and does not include effects such as crop residues or variations in yield levels. The aim of this study was to propose a fertilizer recommendation system for carrot cultivation (FERTICALC Carrot) which includes consideration of the nutrient supply by crop residues, variation in intended yield, soil chemical properties, and the growing season (winter or summer). To obtain the data necessary for modeling nutritional requirements, 210 carrot production stands were sampled in the region of Alto Paranaíba, State of Minas Gerais, Brazil. The dry matter content of the roots, the coefficient of biological utilization of nutrients in the roots, and the nutrient harvest index for summer and winter crops were determined for these samples. To model the nutrient supply by the soil, the literature was surveyed in regard to this theme. A modeling system was developed for recommendation of macronutrients and B. For cationic micronutrients, the system only reports crop nutrient export and extraction. The FERTICALC which was developed proved to be efficient for fertilizer recommendation for carrot cultivation. Advantages in relation to official fertilizer recommendation tables are continuous variation of nutrient application rates in accordance with soil properties and in accordance with data regarding the extraction efficiency of modern, higher yielding cultivars.

Site-Specific Nutrient Management under Rice-Based Cropping Systems in Indo-Gangetic Plains: Yield, Profit and Apparent Nutrient Balance

High fertilizer use efficiency in rice (Oryza sativa L.)-based cropping systems in Indo-Gangetic Plains (IGP) is not achieved because farmers’ fertilizer practices (FFP) and blanket state recommendations (BSR) do not take into account the site-specific variability of nutrient availability in the soil. We evaluated the site-specific nutrient management (SSNM) option against existing FFP, blanket state recommendation (BSR), improved BSR (IBSR i.e., 25 % higher than BSR), and state soil testing laboratory recommendation (STLR) in six pre-dominant rice-based cropping systems namely wheat–rice (W–R), mustard–rice (M–R), potato–rice (P–R), garlic–rice (G–R), chickpea–rice (C–R) and berseem fodder–rice (B–R) in terms of yield gain, economics, nutrient harvest index, soil fertility, and apparent nutrient balances. System rice equivalent yield (SREY) improved by 15.7, 9.5, 13.9 and 30 %, in SSNM over BSR, IBSR, STLR and FFP, respectively. SSNM involved additional cost of ₹ 2940–5291 ha−1 over BSR and ₹ 5492–10120 ha−1 over FFP under different cropping systems but contributed higher added net return of ₹ 23236–75056 ha−1 and ₹ 39577–143899 ha−1 over BSR and FFP, respectively. The output: input ratio and nutrient harvest index for N, P, K were also highest in SSNM. At the end of the experiment, soil available N, Olsen-P and available K content were either maintained or improved over their initial values in SSNM treatments, whereas soil available K in FFP declined by −1.65 % and increased over initial content in BSR and STLR in 0–15 cm soil profile depth. After three crop cycles, apparent N and P balances were positive in all the cropping systems and fertilizer treatments; only exception was a negative N balance in C–R and B–R systems in different fertilizer treatments. The apparent K balances were negative in all the cropping systems irrespective of nutrient management options. But, the magnitude of negative balance was lower in plots received SSNM treatment as compared to other nutrient management strategies, indicating a potential for improving yields, nutrient use efficiency and farm profit without deteriorating soil fertility in different rice based systems in IGP.

Growth Behavior, Nutrient Harvest Index, and Soil Fertility in Okra-Pea Cropping System as Influenced by AM Fungi, Applied Phosphorus, and Irrigation Regimes in Himalayan Acidic Alfisol

The impact of arbuscular mycorrhizal fungi (AMF), inorganic phosphorus (P), and irrigation regimes was studied in an okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system in an acidic Alfisol. Experimentation was carried out at Palampur, India, in a randomized bock design (RBD), replicated three times with fourteen treatments comprising AM fungi (Glomus mosseae), inorganic phosphorus (50, 75, and 100% soil-test-based recommended P dose), irrigation regimes (at 40 and 80% available water capacity), generalized recommended NPK and irrigations (GRD), and farmers’ practice. Effects of AM fungi on plant height, leaf area index (LAI), and dry-matter accumulation (DMA) were nominal at early crop growth stage, i.e., 50 DAS (days after sowing). However, at 100 DAS, AMF imbedded treatments led to higher plant height (4%), LAI (3%), and DMA (6%) in okra, whereas in pea the magnitude of increase in these parameters following AMF inoculation was 6, 5, and 8%, respectively, over non-AMF counterparts. AMF + 75% soil-test-based P dose at either of these irrigation regimes gave statistically similar yields in both okra and pea as that obtained under 100% soil-test-based P dose at either of two irrigation regimes, thus indicating an economy of about 25% in soil-test-based P dose. Regarding nutrient harvest index in okra and pea, statistically similar values were registered with most nutrients under both AMF inoculated and non-AMF counterparts. In the case of okra, P harvest index was registered less by 3% with AMF inoculation; however, its magnitude increased by 3% in pea following AMF inoculation compared to non-AMF counterparts at similar levels of P and irrigation. At completion of two cycles of okra-pea system, AMF imbedded treatments did not alter available soil nutrient status significantly in comparison to non-AMF counterparts. Overall, current study suggests that practice of AMF inoculation has great potential in enhancing growth parameters for better productivity, fertilizer-P economy, and nutrient harvest efficiency in okra-pea production system in Himalayan acidic Alfisol.

Effect of site-specific nutrient management on yield, profit and apparent nutrient balance under pre-dominant cropping systems of Upper Gangetic Plains

A field experiment was conducted on a Typic Ustochrept soil at Project Directorate for Farming Systems Research Modipuram (2904' N, 77046' E, 237m asl), for three consecutive years (2007-08 to 2009-10) to evaluate the sitespecific nutrient management (SSNM) option against existing farmers fertilizer practices (FFP), state recommendation (SR), improved SR (ISR) (i.e. 25% higher than SR), and soil testing laboratory recommendation (STLR) in six predominant wheat based cropping systems of Upper Gangetic Plains, in terms of yield gain, economics, nutrient harvest index, soil fertility, and apparent nutrient balances. SSNM improved system wheat equivalent yield over SR, ISR, STLR and FFP by 19%, 8%, 17% and 29%, respectively. SSNM involved additional cost of Rupees 5 097 to 7 938 /ha over SR and FFP under different cropping systems but it gave higher added net return of Rupees 13 649 to 58 776 /ha and Rupees 25 030 to 68 980 /ha over SR and FFP, respectively. The output: input ratio and nutrient harvest index were also highest in SSNM. At the end of the experiment, soil available N, Olsen-P and available K content were either maintained or improved over its initial values in SSNM treatments, whereas these parameters declined or marginally increased over the initial contents under FFP and SR in 0-15 cm soil profile depth. After 03-crop cycles, apparent N and P balances were positive in most of the cropping systems and fertilizer treatments, except a negative N balance was noticed in pigeonpea [Cajanus cajan (L.) Millsp]–wheat (Triticum aestivum L.) and groundnut (Arachis hypogaea L.)–wheat systems under SR and SSNM treatments. The apparent K balances were negative across all the cropping systems and nutrient management options but the magnitude was lower under SSNM.

Effect of Super-optimal Dose of NPK Fertilizers on Nutrient Harvest Index, Uptake and Soil Fertility Levels in Wheat Crop under a Maize (Zea maysL.)-Wheat (Triticum aestivumL. Cropping System)

A field experiment was conducted in an Inceptisol (IARI, New Delhi, India) during 2010–2011 and 2011–2012 to investigate the effect of optimal (100% NPK) to super-optimal doses (200% NPK) of mineral fertilizer on yield attributes, nutrient harvest index and their uptake pattern in wheat (Triticum aestivum) crop under a maize-wheat cropping systems. Ten levels of fertilizer N, P and K along with 3% foliar spray of iron were laid out in a randomized manner in three replications. Proportionate increase in fertilizer doses of NPK increases the wheat grain (+5.4–5.6%) and straw yield (+5.1–6.1%), but the rate of increase in yield declines as we move from lower to higher doses. The change or increased yield under treatments representing higher doses of NPK is attributed to the increase number of spikes (+4.7–56%) and the weight of grains in each spike (+5–6%). Super-optimal dose of mineral fertilizers (200% NPK) application increased the nutrient contents and uptake of nutrients in grain and straw of wheat. Fertility status of soil after the harvest of two cycles of maize-wheat crop increased with increased application of N, P and K. Nutrient harvest indices for various nutrients showed the effectiveness of mineral fertilizers and foliar iron application increased iron harvest index+9–20%.

Establishment Methods and Weed Management Effects on Productivity and Soil Fertility in Wetland Rice (Oryza sativaL.)

Field experiments in 2010 and 2011 was conducted to evaluate the effect of integrated weed management practices on productivity, nutrient uptake, nutrient harvest index and residual soil fertility status in wetland rice (Oryza sativa L.) under different establishment methods. Wetland rice under system of rice intensification (SRI) method gave significantly higher grain productivity. However, hand weeding twice at 20 and 40 days after transplanting (DAT) was similar with butachlor 50 EC at 1.5 kg a.i. ha−1 at 3 DAT + cono-weeding at 20 DAT. Total uptake of N, P and K by wetland rice was recorded higher with SRI followed by integrated crop management and conventional rice culture. Hand weeding twice at 20 and 40 DAT recorded significantly higher N, P and K uptake in grain and straw followed by butachlor 50 EC at 1.5 kg a.i. ha−1 at 3 DAT + cono-weeding at 20 DAT. The highest nitrogen harvest index (NHI), phosphorus harvest index (PHI) and potassium harvest index (KHI) (79.8, 58.8 and 36.6%), respectively were recorded with cono-weeding twice at 20 and 40 DAT. The residual soil pH, OC, MBC and available N, P and K was significantly higher in SRI method with hand weeding twice at 20 and 40 DAT. Hence, integrated weed management with butachlor 50 EC at 1.5 kg a.i. ha−1 + cono-weeding at 20 DAT performed well under SRI method. However, hand weeding twice at 20 and 40 DAT performed better under ICM method in terms of productivity and better soil health in wetland rice ecosystem.

Reprint of “Developing phosphorus-efficient crop varieties—An interdisciplinary research framework”

Crop production relies on continuous input of large amounts of phosphorus (P) in form of mineral fertilisers manufactured from phosphate rock (PR), a finite resource likely to be depleted within a century. Developing crop varieties with enhanced efficiency for P will make a key contribution to sustainable use of P resources. Crop yield (Yseed) in the context of nutrient-use efficiency can be expressed as a function of total accumulated nutrient in the plant (Nutaccum), nutrient harvest index (NutHI, the fraction of total accumulated nutrient in the plant that is allocated to the seed), and seed nutrient concentration (%Nutseed): Yseed=Nutaccum (NutHI/%Nutseed). In this paper, we review the physiological traits and processes affecting the components of this simple model for improving the P-use efficiency of crops, with a particular focus on root architectural traits for enhancing P-acquisition efficiency (PAE) and hence Nutaccum. As field-grown crops commonly encounter a combination of various abiotic stresses, the potentially negative effects of root architectural traits for improved P acquisition on crop water uptake are also considered.Given that P efficiency at whole-plant level is a complex multi-genic trait governed by interactions between genetic, environmental, and management factors (G×E×M), we then highlight the potential and limitations of root architectural and crop simulation models for evaluating the utility of root adaptive traits for P uptake and crop yield. Furthermore, the application of crop models for assessing the long-term impacts of P-efficient genotypes on soil P dynamics and productivity of cropping systems under current and future climatic conditions is addressed. We then present the components of an interdisciplinary research framework for exploiting genetic diversity in root traits for developing new P-efficient crop varieties and cropping systems in order to (i) lower the critical soil-P levels for optimum crop yields, thereby allowing crop production at lower soil-P loads, (ii) improve the internal P-cycling and crop productivity in low-input and organic cropping systems, (iii) reduce the inefficient use of P fertilisers in fertilised and intensive systems, (iv) improve the environmental sustainability of cropping systems by reducing the potential risk of soil-P losses to water bodies.

Developing phosphorus-efficient crop varieties—An interdisciplinary research framework

Crop production relies on continuous input of large amounts of phosphorus (P) in form of mineral fertilisers manufactured from phosphate rock (PR), a finite resource likely to be depleted within a century. Developing crop varieties with enhanced efficiency for P will make a key contribution to sustainable use of P resources. Crop yield (Yseed) in the context of nutrient-use efficiency can be expressed as a function of total accumulated nutrient in the plant (Nutaccum), nutrient harvest index (NutHI, the fraction of total accumulated nutrient in the plant that is allocated to the seed), and seed nutrient concentration (%Nutseed): Yseed=Nutaccum (NutHI/%Nutseed). In this paper, we review the physiological traits and processes affecting the components of this simple model for improving the P-use efficiency of crops, with a particular focus on root architectural traits for enhancing P-acquisition efficiency (PAE) and hence Nutaccum. As field-grown crops commonly encounter a combination of various abiotic stresses, the potentially negative effects of root architectural traits for improved P acquisition on crop water uptake are also considered.Given that P efficiency at whole-plant level is a complex multi-genic trait governed by interactions between genetic, environmental, and management factors (G×E×M), we then highlight the potential and limitations of root architectural and crop simulation models for evaluating the utility of root adaptive traits for P uptake and crop yield. Furthermore, the application of crop models for assessing the long-term impacts of P-efficient genotypes on soil P dynamics and productivity of cropping systems under current and future climatic conditions is addressed. We then present the components of an interdisciplinary research framework for exploiting genetic diversity in root traits for developing new P-efficient crop varieties and cropping systems in order to (i) lower the critical soil-P levels for optimum crop yields, thereby allowing crop production at lower soil-P loads, (ii) improve the internal P-cycling and crop productivity in low-input and organic cropping systems, (iii) reduce the inefficient use of P fertilisers in fertilised and intensive systems, (iv) improve the environmental sustainability of cropping systems by reducing the potential risk of soil-P losses to water bodies.

Effect of Planting Method on Grain Quality and Nutrient Utilization for No-Tillage Rice

Field experiments were conducted over 2 years using six rice (Oryza Sativa L.) cultivars to investigate the effect of two planting methods, transplanting (TP) and direct sowing (DS), on grain quality and nutrient utilization. Brown and head rice percentages, grain width, amylase, and protein content were greater in TP than in DS, whereas the opposite effect was found for chalkiness rate, gel consistency, and alkali spread value (ASV). Dramatic differences were also found between the two planting methods for nutrient harvest index and utilization efficiency, with TP having greater phosphorus (P) and potassium (K) harvest indexes, nitrogen (N) and K utilization efficiencies, and lower N harvest index and P utilization efficiency than DS. Moreover, significant differences between these genotypes could be found for both nutrient harvest index and utilization efficiency. The correlation analysis showed that rice chalkiness, transparency, gel consistency, amylose, and protein contents were all significantly correlated with N, P, and K nutrient traits. In addition, significant interactions between rice cultivar and planting methods for both rice quality and nutrient traits were also found.

Effect of integrated crop management practices on root-shoot characteristics, yield and nutrient harvest index of pigeon pea (Cajanus cajan) under irrigated north Indian Plains

A field experiment was conducted during rainy season of 2017 at experimental farm of ICARIndian Agricul- tural Research Institute, New Delhi under pigeonpea [Cajanus cajan (L.) Millsp]wheat [Triticum aestivum L.] crop- ping system to assess the effect of different integrated crop management (ICM) modules [04 conventional tillage (CT) based: (ICM ICM ); 04 conservation agriculture (CA) based: (ICM ICM ); 01 organic agriculture based: 1 4 5 8 (ICM )] on root-shoot characteristics, seed yield and nutrient harvest index (NHI) in pigeon pea. The experiment 9 was planned in a randomized block design with 03 replications. The results show that ICM modules (ICM , ICM , 8 6 ICM , and ICM ) supplied with 75% NPK through chemical fertilizers + arbuscular mycorrhizal fungi (AMF) + NPK- 4 2 biofertilizer (NPK-bf) had an edge over the 100% NPK alone supplied ICM , ICM , ICM , ICM modules with re- 7 5 3 1 spect to root characteristics. However, branches/plant (22.7) and pigeon pea productivity (1.92 t/ha) were signifi- cantly higher under ICM module over ICM . Similarly, the 100% NPK supplied ICM modules had an edge over 7 8 75% NPK + AMF + NPK-bf supplied ICM modules with respect to number of branches/plant and seed yield owing to balanced supply of plant nutrients readily available to crop. The effect of different ICM modules on nutrient har- vest index (NHI) for NPK was found non-significant. In general, the CA based ICM modules showed an edge over CT based ICM modules with respect to root-shoot characteristics, seed yield and NHI. Overall, the CA based mod- ules like ICM and ICM can be recommended to the farmers for enhancing the crop productivity in pigeon pea 7 8 alone or on pigeon peawheat cropping system based in irrigated Indo-Gangetic plains region.

Tillage and nutrient-management effects on productivity, profitability and resource-use efficiency of wheat (Triticum aestivum) in foothills region of Uttarakhand

A study was carried out during 2013-14 and 2014-15 at the Norman E. Borlaug Crop Research Centre, Pantnagar, representing the foothills (Tarai) region of Uttarakhand, India, to study the effect of tillage and nutrient management on growth productivity, profitability and resource use efficiency of wheat (Triticum aestivum L.). The experimental site was silty clay loam having soil pH 7.21, organic carbon 0.68% and 242.42, 22.56 and 240.32 kg/ ha available N, P2O5 and K2O respectively. The results indicated that the wheat planted on permanent raised bed system (PRBS) and furrow-irrigated raised bud system (FIRBS) had higher plant height, dry matter accumulation, chlorophyll content but subsoiling (SS) gave higher leaf-area index (LAI) followed by minimum tillage (MT) and PRBS. Similarly, significantly higher crop-growth rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR) were recorded under PRBS and FIRBS but leaf-area rtio (LAR) was higher under SS followed by conven tional tillage (CT). The yield attributes like effective tillers and grains/ear were significantly higher under PRBS and FIRBS. These resulted in ~9.5 and 16% higher grain yield of wheat than CT and MT respectively. The harvest in dex (HI), partial factor productivity (PFP) and nutrient harvest index (NHI) were significantly higher under FIRBS and PRBS tillage systems. Among the nutrient management, recommended dose of fertilizer (RDF) had greater plant height, dry-matter accumulation, chlorophyll content, LAI, CGR, LAR, effective tillers, grains/ear. The grain yield of wheat was 11.7 and 48.6% higher than SSNM and 50% RDF respectively. The HI, PFP and NHI were found significantly higher at 50% RDF followed by site-specific nutrient management (SSNM). Thus, wheat planted either on PRBS or FIRBS with application of recommended dose of fertilizers 150 kg N+26.4 kg P + 33.3 kg K/ha may be used for higher productivity, profitability and resource-use efficiency of wheat in tarai region of Uttrakhand and also be replicated in similar agro-ecology of India

Productivity, profitability and nutrient-use efficiency of baby corn (Zea mays) as influenced of varying fertility levels

A field experiment was conducted at Varanasi during the 2 consecutive pre-kharif (rainy) season of 2012 and 2013, to work out the optimum levels of NPKS and Zn application for maximizing the yield, monetary returns and nutrient-use efficiency of baby corn (Zea mays L.). Baby cob, baby corn and green fodder yields, economics and nutrient uptake (N, P, K, S and Zn) were significantly higher with application of 125% recommended dose of fertil- izer (RDF). Further, application of 50 kg S/ha resulted in significant increase of baby cob, baby corn, green fodder yields, net profit and nutrient uptake (N, P, K, S and Zn) over the control, but it remained at par with 25 kg S/ha. Similar trend were observed with application of zinc levels also. Increasing levels of sulphur and zinc application progressively reduced the agronomic and physiological efficiency and apparent recovery of baby corn. In general, these indices were noted markedly higher with application of 25 kg S/ha and 5 kg Zn/ha than 50 kg S/ha and 10 kg Zn/ha, respectively. However, nutrient-harvest index of N, P, K were decreased gradually with application of in- creasing levels of NPKS and Zn but reverse in case of S and Zn application. Hence application of 125% RDF along with 50 kg S/ha and 10 kg Zn/ha was found optimum to obtain the maximum baby corn yield, net profit and nutrient-use efficiency under irrigated conditions of Varanasi, Uttar Pradesh.

Macro‐ and micronutrients removed by upland and lowland rice cultivars in West Africa

Plant analysis is an important component of soil fertility and plant nutrition research. Plant analysis at harvest of the crop forms the basis for constructing nutrient balances and assessing the nutrient needs of production systems. Amounts of macro‐ and micronutrient elements removed by improved, upland and lowland rice cultivars were determined in field experiments at two sites in Ivory Coast. Amounts of nitrogen (N), zinc (Zn), and manganese (Mn) removed for 11 rice grain yield by upland and lowland rice cultivars were similar, but the amounts of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) removed were higher for lowland than upland rice. The nutrient element harvest indexes (amount in grain/amount in grain plus straw) varied between the cultivars, but more importantly, among nutrient elements. On average the nutrient harvest index was highest for P (69%) and lowest for K (10%). The results suggest that the nutrient requirement of rice for K can be met to a large extent through the recycling of K in rice straw. The amounts of other major nutrients, N and P in the straw were small and hence less scope for supplying these nutrients through the recycling of rice straw.