Split Application Of Nitrogen Research Articles

Growth and yield variability of wheat as effected by split application of potassium and nitrogen

Growth and yield variability of wheat as effected by split application of potassium and nitrogen

Response of chickpea's yield and yield components to double inoculation with mycorrhiza and rhizobium under split application of nitrogen

AbstractThe utilization of advantageous microorganisms as a biofertilizer has gained significant importance in the agricultural industry due to their potential contribution to food safety and the sustainable cultivation of crops. To evaluate the effect of nitrogen (N) fertilizer and co‐inoculation with arbuscular mycorrhiza and rhizobium on the yield and yield component of chickpea (Cicer arietinum L.), a 2‐year field experiment was conducted in 2020–2021 at the Agricultural Research Station of Ferdowsi University of Mashhad, Iran. The experiment was designed as a randomized block trial in factorial design with three replicates. The treatments included two levels of inoculation (noninoculated and inoculated with rhizobium and mycorrhiza) and application of different levels of N fertilizer (0, 25, or 50 kg ha−1) at three growth stages (sowing, flowering, pod filling) as follows; F0 (0,0,0), F1 (25,0,0), F2 (25,25,0), F3 (25,25,25), F4 (50,0,0), F5 (50,50,0) and F6 (50,50,50), respectively. The results showed that seed inoculation and split N fertilization significantly increased yield and yield components in chickpea (Cicer arietinum L.). Seed inoculation showed the highest values for all traits studied compared to the noninoculated treatments. Moreover, among the fertilizer treatments, the highest values for plant height (41.8 cm), number of branches (9.1), number of grains per plant (17.8) and 100‐grain weight (30.4 g) from F6 through the F3 treatment, were statistically similar. The results show that the effect of inoculation is more significant when a lower amount of N fertilizer is applied. Due to the health and environmental problems associated with chemical fertilizers, double inoculation and split application of N fertilizers at lower doses can be recommended.

Grain protein and amino acid dynamics in sorghum with in‐season split‐nitrogen application

AbstractBackground and ObjectivesField experiments were conducted to assess the influence of in‐season split application of nitrogen (N) on grain protein, protein digestibility, and amino acid dynamics in grain sorghum, in three different environments. Treatments included a zero N check and eight treatments with varying N application timings and amounts.FindingsThe five high N treatments had significantly greater grain protein content than all the lower N treatments. As the total protein increased, the kafirin portion of the protein increased, whereas the albumin‐globulin levels decreased. Nitrogen treatment had a significant effect on 13 of the 18 amino acids. High N applications significantly increased amino acids on a protein basis including alanine, glutamic acid, leucine, proline, and phenylalanine.ConclusionsTreatment N92 with N applied at 92 kg N ha−1 as split application at three different growth stages including planting, panicle initiation, and booting emerged as the optimum N treatment for increasing protein and amino acid concentration in grain sorghum.Significance and NoveltyThe ideal N application approach identified can be used to screen a wide range of sorghum hybrids under varying levels of irrigation and the same N treatments can be adopted by producers to enhance grain protein in sorghum.

An Agronomic Efficiency Analysis of Winter Wheat at Different Sowing Strategies and Nitrogen Fertilizer Rates: A Case Study in Northeastern Poland

This study was undertaken to examine the influence of the sowing date, sowing density, and split spring application of nitrogen (N) fertilizer on plant density, tillering, yield components, and grain yields of winter wheat (Triticum aestivum L.) grown in northeastern Poland between 2018 and 2021. The experiment had a split-plot design with three sowing dates (early (3–6 September), delayed by 14 days, and delayed by 28 days), three sowing densities (200, 300, and 400 live grains m−2), and three split spring N rates (40 + 100, 70 + 70, and 100 + 40 kg ha−1 applied in BBCH stages 22–25 and 30–31, respectively). The number of spikes m−2 increased by 11% on average when winter wheat was sown with a delay of 14 days (17–20 September) and 28 days (1–4 October). The number of spikes m−2 was highest when winter wheat was sown at 300 and 400 live grains m−2. The application of 100 + 40 kg N ha−1 (BBCH 22–25 and 30–31, respectively) increased the number of spikes m−2. An increase in sowing density from 200 to 300 to 400 live grains m−2 decreased the number of grains spike−1 by 5% and 7%, respectively. Thousand grain weight (TGW) increased by 1% and 2% when sowing was delayed by 14 (17–20 September) and 28 days (1–4 October), respectively. In northeastern Poland, grain yields peaked when winter wheat was sown between 17 September and 4 October (10.52–10.58 Mg ha−1). In late-sown winter wheat, grain yields increased due to a higher number of spikes m−2 and higher grain weight. The highest sowing density (400 live grains m−2) induced a greater increase in grain yields than the lowest sowing density (200 live grains m−2) (10.25 vs.10.02 Mg ha−1). In winter wheat sown at a density of 400 live grains m−2, the increase in grain yields resulted in a higher number of spikes m−2. Grain yields peaked in response to 100 kg N ha−1 applied in BBCH stages 22–25 and 40 kg N ha−1 applied in BBCH stages 30–31 (this split N rate increased the number of spikes m−2). In turn, the highest straw yield (6.23 Mg ha−1) was obtained when the second split of N fertilizer was applied in BBCH stages 30–31 (40 + 100 kg N ha−1). Straw yields decreased significantly (by 6%) when winter wheat was sown late (early October). Delayed sowing (mid-September and early October) increased the harvest index (HI) of winter wheat by 5–7%. Split spring N application influenced grain and straw yields, but it had no effect on the HI of winter wheat.

Effect of Need-based Nitrogen Scheduling on the Growth and Productivity of Pearl Millet (Pennisetum glaucum)

Background: Under the present context of global warming and climate change, the choice of an ecologically hardy crop is having prime importance. Nutrient management is an important approach for improving crop growth and productivity. Among all the nutrients, nitrogen helps in the overall growth of the plant. Nitrogen helps to synthesize chlorophyll and thereby supports building the protein units that enhance plant growth. As nitrogen is highly mobile, it is lost through different ways such as volatilization, leaching, nitrification, etc. Split application of nitrogen through proper scheduling is an important approach to reduce nitrogen loss as well as to improve nitrogen use efficiency. Hence, the investigation was conducted to find out how the scheduling of nitrogen is affecting pearl millet growth and productivity. Methods: The present study was conducted in kharif season of 2022 on pearl millet at Post Graduate Experimental Farm, M. S. Swaminathan School of Agriculture. The experiment was carried out in randomized complete block design with 3 replications and 9 treatments, namely, T1: control, T2: 50% basal RDN, T3: 100% basal RDN, T4: 50% basal RDN + 50% at 30 DAS, T5: 50% basal RDN + 25% at 30 DAS and 45 DAS, T6: 50% nitrogen as basal + topdressing @10 kg nitrogen/ha at sufficiency index less than 95%, T7: 50% nitrogen as basal + topdressing @10 kg nitrogen/ha at sufficiency index less than 90%, T8: 50% nitrogen as basal + topdressing @10 kg nitrogen/ha at sufficiency index less than 85%, T9: 50% nitrogen as basal + topdressing @10 kg nitrogen/ha at sufficiency index less than 80%. Result: The results showed that the application of 50% nitrogen as basal + topdressing @10 kg nitrogen/ha at sufficiency index less than 95% gave the maximum growth, yield, and income was also significantly higher with this application. So, it could be recommended to the farmers for growing pearl millet during kharif season in southern Odisha to achieve higher growth and productivity.

Growth parameters and yield attributes as influenced by doses and split application of nitrogen on wheat in acidic soils of Meghalaya

Growth parameters and yield attributes as influenced by doses and split application of nitrogen on wheat in acidic soils of Meghalaya

Effect of Split Application of Nitrogen Levels in Summer Pearlmillet (Pennisetum glaucum L.)

A field experiment was conducted at Sardarkrushinagar Dantiwada Agricultural University, Gujarat during summer season of 2022 on loamy sand. The experiment comprised of nine treatment combinations. Significantly higher plant height, earhead/plant, length of earhead, girth of earhead, test weight, grain and straw yield as well as protein content were recorded under 120 kg N/ha and application of nitrogen at 25% as basal + 75% as top dressing. The same level of nitrogen along with split application of nitrogen provided maximum net realization value and BCR. Application of 150 kg N/ha and split application of nitrogen 40% as basal + 60% as top dressing were at par with 120 kg N/ha and 25% as basal + 75% as top dressing, respectively.

Effect of split application of nitrogen and nano-urea supplementation on growth,yield and economics of linseed (Linum usitatissimum L.)

A field experiment was conducted during rabi, 2021-22 at MARS, UAS Raichur, Karnataka to study the effect of split application of nitrogen and nano-urea supplementation on growth and yield of linseed (Linum usitatissimum L.). The results revealed that application of 100 % N (Two Splits - 50% N as basal + 50% N as top dressing) recorded higher seed yield of linseed which was found at par with the 75% N (Two Splits - 50% N as basal + 50% N as top dressing). The growth parameters, yield attributes and seed yield of linseed was significantly higher with two sprays of nano-urea @ 3ml /litre each at flower initiation stage and capsule development stage, which was found almost at par with the two sprays of 2% urea at flower initiation and capsule development stage. Economic analysis revealed that higher gross monetary returns and net monetary returns were noticed under the application of two sprays of nano-urea @ 3ml /litre each at flower initiation stage and capsule development stage.

Effect of Pearl Millet (Pennisetum glaucum L.) to Split Application of Nitrogen at Different Stages under Irrigated Conditions

A field experimentation was conducted at carried out during kharif 2022 at research farm, Vivekananda Global University, Jaipur. The objectives were to study the effect of nitrogen and split application of nitrogen on growth and productivity of pearl millet. The experiment consisted of 9 treatment combinations comprising three levels of nitrogen (100% RDN (60 kg N/ha), 125% RDN (75 kg N/ha) and 150% RDN (90 kg N/ha) with three levels of split application of nitrogen (Full dose of N at sowing, ½ N at sowing + ½ N at tillering (20-25 DAS) and 1/3 N at sowing + 1/3 N at tillering (20-25 DAS) + 1/3 N at boot stage (35-40 DAS)). The experiment was laid out in split plot design and replicated thrice. The result revealed that levels of nitrogen significantly influenced highest plant height (cm), dry matter accumulation at different stages, chlorophyll content in leaf at 60 DAS, number of effective tillers per plant, length of ear, test weight, grain, stover, biological yields, NPK content and their uptake and protein content with the application of 125% RDN (75 kg N/ha) over 100% RDN (60 kg N/ha). Significantly higher net return (Rs 56315/ha) and highest B:C ratio (2.03) were also obtained with 125% RDN (75 kg N/ha). Further, the split application of nitrogen significantly influenced plant height (cm), dry matter accumulation, chlorophyll content in leaf at 60 DAS, number of effective tillers per plant, length of ear, test weight, grain, stover, biological yields, NPK content and their and protein content with the application of 1/3 N at sowing + 1/3 N at tillering (20-25 DAS) + 1/3 N at boot stage (35-40 DAS) over full dose of N at sowing and ½ N at sowing + ½ N at tillering (20-25 DAS). This treatment also increased significantly net return (Rs 67552/ha) and B:C ratio (2.45) rest of the treatments

A single nitrogen application maintains wheat yield and quality in dryland Mediterranean Vertisol

AbstractIn dryland Mediterranean Vertisols, split nitrogen (N) application is usual in wheat crops. Because of the high clay content of these soils and the low rainfall, a single application might offer ecological and economic benefits without yield loss. We conducted a 5‐year study as part of a long‐term experiment and compared the split application of N (50% at tillering, 50% at stem elongation phase) with a single application (tillering) in 10 cropping systems resulting from the combination of type of cultivation (no‐till and conventional tillage) and 2‐year crop rotations (wheat–wheat, wheat–fallow, wheat–chickpea, wheat–faba bean and wheat–sunflower). Depending on the system × crop rotation interaction, a single application of 100 or 150 kg N ha−1 maintained grain yield, protein content and apparent N recovery, with no effect on nitrate content compared with a traditional split application. The average grain yield did not differ between split and single application of N (3.27 and 3.23 Mg ha−1, respectively, for single and split application of 100 kg N ha−1 rate; 3.46 and 3.40 Mg ha−1, respectively, for single and split application of 150 kg N ha−1 rate). The soil nitrate concentration at pre‐seeding in the 0–0.3 m layer showed similar results, except in the case of the wheat–faba rotation, with lower nitrate concentration in the sub‐subplots of single application and no‐till. This work shows that adopting the single N application strategy in rotations on Mediterranean dryland Vertisols will reduce economic and environmental costs.

Irrigation Water and Nitrogen Fertilizer Management in Potato (Solanum tuberosum L.): A Review

Intensive irrigation and nutrient management practices in agriculture have given rise to serious issues in aquifer water depletion and groundwater quality. This review discusses the effects of irrigation and nitrogen management practices on potato growth, yield, and quality, and their impacts on water and nitrogen use efficiencies. This review also highlights the economics and consequences of applying deficit irrigation strategies in potato production. Many researchers have demonstrated that excessive irrigation and nitrogen application rates negatively impact potato tuber yield and quality while also increasing nitrate leaching, energy consumption, and the overall costs of production. An application of light-to-moderate deficit irrigation (10–30% of full irrigation) together with reduced nitrogen rates (60–170 kg/ha) has a great potential to improve water and nitrogen use efficiencies while obtaining optimum yield and quality in potato production, depending on the climate, variety, soil type, and water availability. There is an opportunity to reduce N application rates in potato production through deficit irrigation practices by minimizing nitrate leaching beyond the crop root zone. The best irrigation and nitrogen management techniques for potato production, as discussed in this review, include using sprinkle and drip irrigation techniques, irrigation scheduling based on local crop coefficients, soil moisture content, and crop modeling techniques, applying slow-release nitrogenous fertilizers, split nitrogen application, and applying water and nitrogenous fertilizers in accordance with crop growth stage requirements.

Impact of in‐season split application of nitrogen on intra‐panicle grain dynamics, grain quality, and vegetative indices that govern nitrogen use efficiency in sorghum

AbstractBackgroundThe correct rate and timing of nitrogen (N) has the potential to improve sorghum productivity through modified grain yield components and quality. The impacts of in‐season split application of N have little documentation.AimAn experiment was conducted to determine the optimum rate and timing of N to relate vegetative indices that govern nitrogen use efficiency and to maximize grain yield and quality under different soil types.MethodsPioneer 86P20 was grown in three environments on two different soil types following a completely randomized block design with nine N application treatments. Treatments included differing N rates applied at critical developmental stages of sorghum (planting, panicle initiation, and booting), accompanied with high temporal aerial phenotyping.ResultsOpportunities to increase grain protein content while using split N applications were observed, with panicle initiation identified as a critical developmental stage. In‐season split application of N enhances grain yield under low soil mineral N. Split application of 31 kg N ha−1 each at the time of planting, panicle initiation, and booting emerged as optimum N treatment to increase protein content in sorghum. Vegetative indices, that is, normalized difference vegetation index and normalized difference red edge index are capable of predicting grain yield and protein content, respectively. Intra‐panicle grain numbers and weights were altered significantly at different portions within panicles, with an opportunity to enhance yield potential at the bottom portion. The strong stay‐green trait in this hybrid locked a large proportion of nitrogen in the leaves, which warrants the need for balancing stay‐green and senescence in sorghum improvement programs.ConclusionsFindings highlight that in grain sorghum remobilization of residual leaf N into grain is a target to increase yield and grain quality. An optimized stay‐green trait balanced with senescence is recommended for enhancing sorghum yield potential.

Enhancing maize profitability through altering split application of nitrogen and potassium at different stages

Enhancing maize profitability through altering split application of nitrogen and potassium at different stages

Response of Potato (Solanum tuberosum L.) to Split Application of Nitrogen under North Gujarat Agro-Climatic Condition

A field experiment was conducted during rabi 2018-19 and 2019-20 to study the effect of split application of nitrogen under mini sprinkler system on potato yield and economics in North Gujarat Agro-climatic condition on loamy sand soil at Potato Research Station, Sardarkrushinagar Dantiwada Agricultural University, Deesa. The Recommended dose of fertilizer (RDF) of potato for North Gujarat is 275:138:275 NPK kg/ha. The results revealed that the significantly higher total tuber yield (67.81 t/ha) and net return (`206104/ha) was recorded in 50 % N (103 kg) as basal and remaining 50 % N (103 kg) in two equal splits at 30 and 45 DAP along with 110 P2O5 and 275 kg K2O/ha as basal application with saving of 25 % N under North Gujrat Agro-climatic condition of Gujarat.

Studies on the Effect of Split Application of NPK fertilizers on Growth and Yield of Papaya under Central Dry Zone of Karnataka

A field experiment was conducted at Eswargere village, Hiriyur taluk, Chitradurga district during the year 2020-2021 to assess the effects of split application of nitrogen, phosphorus, and potassium (NPK) fertilizer on papaya growth and yield, and the experiment was set up in Randomized Complete Block Design. The treatments include seven treatments comprising varying rates (75, 100 and 125% recommended dose of fertilizers) and time of application (Bimonthly and monthly intervals). Among growth attributes plant height (186.70 cm), stem girth (46.38) was recorded highest in 125% RDF through split application. In yield attributes maximum fruit length (23.54 cm) circumference (44.75 cm), volume (1711.07 cc) firmness (7.43 kg/cm2), total yield (138.83 t/ha) and lowest cavity index (14.84) were also observed in 125% RDF through split. Applying of 125% RDF through split at different growth stages (187.5:156.25:125 N: P2O5: K2O g/plant) in vegetative stage of 4 months, (62.5:125:187.5 N: P2O5: K2O g/plant) in flowering to fruit set stage of 2 months, (62.5:31.25:312.5 N: P2O5: K2O g/plant) in fruit development stage of 3 months at monthly interval showed to be better for fetching maximum plant growth and yield of papaya fruits.

Effects of Crop Geometry and Split Nitrogen Application on Spring Maize Growth, Yield Components and Yield in Digam, Gulmi, Nepal

Maize (Zea mays L.) is a heavy nutrient feeder that needs optimum spacing and appropriate time to apply nitrogen to get maximum yield. A field study was carried out at Digam, Gulmi, from February to June 2022 to examine the impact of crop geometry and split application of nitrogen on spring maize in two factorial randomized complete block design (RCBD) with four replications. Factor A was the split application of nitrogen; (120 kg ha-1N at the time of sowing) and (60 kg ha-1N at the time of sowing + 30 kg ha-1N at knee height stage + 30 kg ha-1N before tasseling stage) and factor B included the three levels of spacing (75 cm x 25 cm, 60 cm x 25 cm and 50 cm x 25 cm). Plant height , stem girth , leaf number, cob girth, thousand grain weight, number of kernel rows per ear, number of kernels per row, and grain yield (3.45 MT ha-1) were all highest for treatment (60 kg ha-1N at sowing + 30 kg ha-1N at knee height + 30 kg ha-1N before tasseling). Likewise, plant height, leaf area index, cob length, cob girth, cob weight, thousand grain weight, number of kernels per row, grain yield (3.04 MT ha-1) and harvest index were highest in plant spaced at (75 cm x 25 cm), while the number of kernel rows per ear was highest in plants spaced at (60 cm x 25 cm). The lowest value of all parameters was found in plants at treatments; (120 kg ha-1N at the time of sowing) and (50 cm x 25cm). Similarly, the treatment (60 kg ha-1N at the time of sowing + 30 kg ha-1N at knee height stage + 30 kg ha-1N before tasseling stage) combined with spacing of (60cm x 25cm) was found to have a significant effect on grain yield (3.99 MT ha-1) which was statistically at par to the treatments, (60 kg ha-1 N at the time of sowing + 30 kg ha-1 N at knee height stage + 30 kg ha-1 N before tasseling stage) combined with spacing of (75 cm x 25 cm) (3.95 MT ha-1 ) . Thus, for the optimum and sustainable production of the spring maize, crop geometry of (75 cm x 25 cm) or (60 cm x 25 cm) can be recommended with three splits application of nitrogen at Digam, Gulmi.

An optimized strategy of nitrogen-split application based on the leaf positional differences in chlorophyll meter readings

Modern rice production faces the multiple challenges of increasing grain yields, reducing inputs of chemical fertilizer. However, the disequilibrium between nitrogen (N) supplement from the soil and the demands for N of plants is a serious obstacle to these goals. Plant-based diagnosis can help farmers with better choice of the time and amount of topdressing of N fertilizer. Our objective was to evaluate a non-destructive assessment of rice N demands based on the relative SPAD value (RSPAD) due to leaf positional differences. In this study, two field experiments were conducted, including a field experiment of different N rates (Exp. I) and an experiment to evaluate the new strategy of nitrogen-split application based on RSPAD (Exp. II). The results showed that higher N inputs significantly increased grain yield in modern high yielding super rice, but at the expense of lower nitrogen use efficiency (NUE). N nutrition index (NNI) can adequately evaluate situations of excessive, optimal, and insufficient N nutrition in rice, and the optimal N rate for modern high yielding rice is higher than conventional cultivars. The RSPAD is calculated as the SPAD value of top fully expanded leaf versus the value of third leaf, which taking into account of non-uniform N distribution within a canopy. RSPAD can be used as an indicator for higher yield and NUE, and guide for better management of N fertilizer. Furthermore, we developed a new strategy of nitrogen-split application based on RSPAD, in which N rate was saved by 18.7%, yield was increased by 1.7%, and agronomic N use efficiency was increased by 27.8%, when compared with farmers’ practices. This strategy of N fertilization showed a great potential in ensuring high yielding and improving NUE at lower N inputs.

Effect of cultivars and split application of nitrogen at the different growth stages on yield and its component of bread wheat (Triticum aes-tivum L.) under rain-fed conditions in Kurdistan, Iraq

To investigate the best N fertilizer application regime for the environment and the economy. Therefore, a field experiment was conducted for one year (2020–2021) under the rain-fed condition at two locations in the Sulaimani region; Qlyasan research field of the College of Agriculture Engineering University of Sulaimani and the Kanipanka research station in the Sharazoor valley to determine the effect of the application of 120 kg ha-1 N in four split doses (T6) at four growing stages, sowing, tillering, booting, and spiking, respectively. Were T1 (60 kg ha-1 N at sowing, 60 kg ha-1 N at tillering) used as a control, T2 (60 kg ha-1 N at sowing, 30 kg ha-1 N at tillering, 30 kg ha-1 N at booting), T3 (60 kg ha-1 N at sowing, 30 kg ha-1 N at tillering, 30 kg ha-1 N at spiking), T4 (60 kg ha-1 N at sowing, 20 kg ha-1 N at tillering, 20 kg ha-1 N booting, 20 kg ha-1 N at spiking), T5 (40 kg ha-1 N at sowing,30 kg ha-1 N at tillering, 30 kg ha-1 N at booting, 20 kg N ha-1 N at spiking) and T6 (40 kg ha-1 N at sowing, 40 kg ha-1 N at tillering, 40 kg ha-1 N at booting) and their effect on grain yield and it’s components of bread wheat cultivars (Adana-99, Hawler-4, and Sulaimani-2). A split plot arrangement within Randomimized Complete Block Design with three replicates was used. The possible comparison among the means was calculated following the Duncan test at a significant level of 0.05. As part of grain yield, no. of spikes m-2, no. of grains.spike, thousand-grain weight (g) (TGW), grain yield ton ha-1 (GY), biological yield ton ha-1 (BY), and Harvest Index (H.I) were all calculated. As the average of both locations of the results showed that the impact of Cultivars on agronomic traits was significant, Sulaimani-2 produced the maximum values for all characters, with the exception of (TGW) and (H.I), which were provided by Hawler-4. All the bread wheat characters were significantly influenced by the time of application of nitrogen, where T5 produced the maximum value for all characters with the exception no. of spike m-2, where T6 had the ultimate value. The no. of spikes m-2 had a significant effect on the T4, and T5 study characters. Based on what we've found, the best combination is Sulaimani-2 with T6 and T5 except in Qlyasan location with T6 only when rain is guaranteed. This increases both the yield and its components.

Split-nitrogen application increases nitrogen-use efficiency and yield of cotton

Split-nitrogen application increases nitrogen-use efficiency and yield of cotton

Evaluating the tradeoff between cost effectiveness and participation in agricultural conservation programs

AbstractUsing a survey of 430 farmer respondents in the Boone and North Raccoon River watersheds in Iowa, we examine the impacts of three program innovations—reverse auctions, spatially targeted payments, and higher offered payments—on agricultural conservation program cost effectiveness and participation by farmers. We combine farmer responses to a discrete choice experiment offering voluntary conservation contracts with township‐level estimates of per‐acre nitrogen reductions from each practice derived from the process‐based ecohydrological Soil and Water Assessment Tool model. Using a random‐parameters logit model, we show that both cost‐reducing and benefit‐boosting interventions reduce budgetary costs per projected pound of nitrogen removed from the watershed for each practice and thus are more cost effective than the prevailing current cost‐share programs. However, we find that these interventions can reduce participation by 30%–70%. Our policy simulations show that even with large budgets, the watershed‐level nitrogen reduction from all policy interventions remains far below the policy targets set by the Iowa Nutrient Reduction Strategy. Furthermore, we find cover crop contracts are far more cost effective than no‐till/strip‐till split nitrogen application contracts.