Conventional Paddy Research Articles

The dynamics of methane (CH4) emissions in organic and conventional paddy fields on Alfisols and Andisols at Karanganyar Regency, Indonesia

The increase in greenhouse gas concentration, one of which is Methane (CH4), is the main cause of global warming and climate change. Organic materials which easily decomposed are the main sources of CH4 production in paddy fields. The research aimed to find out and analyze the dynamics of CH4 emission in each stage of rice growth, seasonal CH4 emission, and rice productivity cultivated both organically and conventionally on Alfisols and Andisols at Karanganyar Regency, Indonesia. All treatments were conducted by local farmers with common agricultural practices. In conventional farming, for Andisols only fertilizer has applied the chemical whereas for Alfisols the chemical fertilizer was applied with the addition of fresh chicken manure. The sampling of CH4 gas conducted four times in each location at 15, 35, 65, and 100 days after planting (DAP), respectively, using box chambers (50×50×100 cm). The gases were analyzed using gas chromatography, while productivity was determined by calculating total yield 2.5 m−2 (Indonesian Statistical Bureau). The treatment of Andisols C (Andisols with Conventional Farming Management) resulted in the highest CH4 emission in paddy fields for one planting season. The highest CH4 emissions were obtained at the active tillering phase (35 DAP), because of the effect of flooded conditions. For both andisols and alfisols conventional farming management resulted in higher rice productivity, whereas organic farming management resulted in better economically and in preserving the environment.

Enhancing water productivity using alternative rice growing practices: a case study from Southern India

AbstractSaving water in irrigated agriculture is a high priority in areas with scarce water resources and impacted by climate change. This paper presents results of measurements on water productivity (WP) under alternative rice growing practices such as alternating wetting and drying, direct seeded rice, modified systems of rice intensification and conventional paddy rice (NI) in two selected districts (Guntur in Andhra Pradesh and Nalgonda in Telangana, India). Under alternative practices, the yields varied from 5.72 to 6.11 t/ha compared with 4.71 t/ha under paddy rice. The average water application varied from 991 to 1494 mm under alternative practices while average application in conventional paddy rice was 2242 mm. Higher yield and lower water application led to an increase in WP varying from 0.45 to 0.59 kg/m3 under alternative practices compared with 0.22 kg/m3 under conventional paddy rice. The measurements showed that less water can be used to produce more crop under alternative rice growing practices. The results are important for water-scarce areas, providing useful information to policy makers, farmers, agricultural departments and water management boards in devising future climate-smart adaptation and mitigation strategies.

Water and soil properties in organic and conventional paddies throughout the rice cultivation cycle in South Korea

Water and soil properties in organic and conventional paddies throughout the rice cultivation cycle in South Korea

Enhanced nitrogen cycling and N2O loss in water-saving ground cover rice production systems (GCRPS)

An alternative to conventional cultivation of rice on submerged paddy soil is the ground cover rice production system (GCRPS), in which soil is covered with a plastic film to reduce the use of irrigation water. However, reduced soil water, increased aeration and temperature under GCRPS could promote soil nitrogen (N) mineralizing, nitrifying and denitrifying microbes and thus enhance soil N turnover and environmental losses e.g., through emission of the potent greenhouse gas nitrous oxide (N2O). At two sites with paired GCRPS and conventional paddy fields in Central China, we followed the abundance and activity of N-mineralizers, nitrifiers, denitrifiers and N2-fixing microbes based on qPCR from DNA and RNA directly extracted from soil. With decreasing soil water during the growing season, GCRPS strongly increased N mineralization as illustrated by several fold increased transcript levels of chiA. Furthermore, GCRPS reduced the nifH transcripts (encoding for nitrogenase) by 38% to 70% but increased the qnorB transcripts by 160% and archaeal amoA (AOA) transcripts by one order of magnitude (encoding for nitric oxide reductase and ammonia monooxygenase). This indicated a higher potential for N losses due to decreased biological N2 fixation, increased N leaching and increased N2O emission in GCRPS. The latter was confirmed by increased in situ N2O emissions. In addition, the N2-fixing and denitrifying microbial community composition as measured by a community fingerprinting approach was strongly influenced by GCRPS cultivation. Hence, our study reveals the microbial mechanisms underlying the risks for increased N mineralization, nitrification and N2O emissions and decreased biological N fixation in GCRPS. However, analysis of topsoil N stocks provided evidence that at least under N fertilizer application, GCRPS might overall maintain soil N stocks. This might result from a GCRPS-induced increase in fertilizer N use efficiency, root development and C and N return via residues, which appear to outbalance the observed effects on nitrification, gaseous N losses and biological N fixation, thereby preventing a net loss of total soil N.

Economic Analysis of Traditional and Sri Method of Paddy Cultivation

The conventional paddy growing tracts are in worst crisis due to social, biological and technical setbacks. Well acclaimed rice bowls in several part of the nation is facing a decline in area, production and productivity. In India, there is a growing demand for rice due to ever escalating population. Rice is consumed both in urban and rural area and its consumption is growing due to high-income elasticity of demand. To meet the growing demand, a rapid income in paddy production is needed. But there is little scope to increase the area; hence increase in production and productivity with an improvement in efficiency of production to act as a technological breakthrough to meet the growing demand.

Theoretical analysis of the effects of irrigation rate and paddy water depth on water and leaf temperatures in a paddy field continuously irrigated with running water

Water management techniques such as continuous irrigation with running water (CIRW) have been used by Japanese farmers to control the thermal environment for rice cropping. In this study, to optimize this method to control the thermal environment in paddy fields, theoretical equations for predicting water and vegetation temperatures in a paddy field were obtained. First, the equations to calculate water and vegetation temperatures in a paddy field were obtained by solving the heat balance equations of the paddy water and vegetation, taking into account the effect of horizontal heat convection driven by irrigation. The equations were validated by comparisons with observed water temperatures in a conventional paddy field under CIRW. The calculated changes in water temperatures over time and distance showed good agreement with observed values, with a root mean square error of 0.39°C. This result indicated that the equations satisfactorily expressed the features of paddy water temperature under CIRW. Next, these equations were used to determine the effects of irrigation rate, paddy water depth and wind speed on water and rice plant temperatures. The following results were obtained. 1) The area cooled by CIRW was positively related to irrigation rate and negatively related to water depth. 2) Low water depths were preferable for application of CIRW during the nighttime. 3) Slower wind speeds and latent heat flux from vegetation strengthened the effects of water management on vegetation temperature. The proposed equations and analyses represent the common features of the effect of irrigation on water and vegetation temperatures in a paddy field, and provide quantitative information about the effects of water management techniques on the thermal environment for rice cropping.

Effect of swine liquid manure application in paddy field on water quality, soil fertility and crop yields

Land application of animal manure has been accepted as an effective method and disposal option, which has economic, environmental and social benefits, while also sometimes exists questions about its impact on soil and water quality and crop yields. This paper presents a field-scale study in Chongming Island, Shanghai, China, where land application of digested swine liquid manure with chemical fertilizer supplement in paddy field (SMC field) was conducted to study the short-term effect on soil quality in different depth, pollutant losses by surface runoff, pollutant concentrations in groundwater and crop yields, compared to conventional paddy field with land application of pure chemical fertilizer (CKC field). The results indicated that: (1) in groundwater, the concentrations of chemical oxygen demand (COD), nitrate nitrogen (Nitrate-N), total phosphorus (TP) and dissolved phosphorus (DP) were significantly increased by 24.69, 17.04, 11.76 and 21.05%, respectively, in the SMC field; (2) in surface runoff, the loss loading of COD, TP and DP was significantly increased by 32.18, 15.46 and 28.13%, respectively, while the ammonia nitrogen (Ammonia-N) was significantly decreased by 31.81%, in the SMC field; (3) in the different depth of soil, the contents of total nitrogen presented a greater decrease in the SMC field, while the contents of TP presented a greater decrease in the CKC field, compared to the properties of original soil; (4) for the crop yields, there was no significant difference between the SMC and CKC field. These practices had proved the feasibility for land application of swine liquid manure in the paddy field, and this approach could be extended after being rate modified to concern the nutrient utilization and pollution risk to water environment.

Organic carbon and nitrogen availability determine bacterial community composition in paddy fields of the Indo-Gangetic plain.

Soil quality is an important factor and maintained by inhabited microorganisms. Soil physicochemical characteristics determine indigenous microbial population and rice provides food security to major population of the world. Therefore, this study aimed to assess the impact of physicochemical variables on bacterial community composition and diversity in conventional paddy fields which could reflect a real picture of the bacterial communities operating in the paddy agro-ecosystem. To fulfill the objective; soil physicochemical characterization, bacterial community composition and diversity analysis was carried out using culture-independent PCR-DGGE method from twenty soils distributed across eight districts. Bacterial communities were grouped into three clusters based on UPGMA cluster analysis of DGGE banding pattern. The linkage of measured physicochemical variables with bacterial community composition was analyzed by canonical correspondence analysis (CCA). CCA ordination biplot results were similar to UPGMA cluster analysis. High levels of species-environment correlations (0.989 and 0.959) were observed and the largest proportion of species data variability was explained by total organic carbon (TOC), available nitrogen, total nitrogen and pH. Thus, results suggest that TOC and nitrogen are key regulators of bacterial community composition in the conventional paddy fields. Further, high diversity indices and evenness values demonstrated heterogeneity and co-abundance of the bacterial communities.

Analysis of Environmental Properties of Paddy Soils with Regard to Seasonal Variation and Farming Methods

The aim of this study is to investigate the environmental properties of paddy soils depending on farming methods and seasonal variation. The paddy soils in 11 plots of conventional paddy and 24 plots of organic paddy were sampled and analyzed in four season of March, May, August, and October. The obtained data of soil properties were used for statistical analysis. A nalysis of variance showed that only NH4-N and P2O5 were significantly different depending on farming methods. However, the differences of all soil properties depending on seasonal variation were strongly significant. Principal component analysis also presented t hat nitrogen and phosphorus concentration in soils were more significantly influenced by seasonal variation than farming method. Electric conductivity in soil was decreased from March to October. Amounts of soil organic matter in August and October were higher than that in March and May. T-N was decreased from March to October. NH4-N and NO3-N in the soil of both conventional and organic paddy were higher in May than other seasons. T-P concentration was found to be highest in August, but P2O5 concentration was lowest in August. It can be concluded that seasonal variation should be considered for analysis and comparison o f soil environmental properties. Key words: Paddy Soil, Soil Chemical Properties, Farming Method, Seasonal Variation, Analysis of Variance, Principal Component Analysis

Natural farming and rice planthoppers in Western Japan

ABSTRACTPlanthoppers are serious pests of rice in both tropical and temperate East Asia. In temperate regions, population density has been shown to be largely determined by the rate and timing of immigration from tropical areas. Historical records of planthopper outbreaks in western Japan over 1300 years suggest that the cropping system may influence planthopper populations as the likelihood of an outbreak has increased substantially since the conversion to intensive rice production during the second half of the twentieth century. To investigate this in more detail, planthopper populations were compared in naturally and conventionally farmed paddies in Hiroshima Prefecture. Naturally farmed paddies differed from conventionally farmed ones in the absence of synthetic chemicals and the use of plant compost as the sole source of fertilizer. Paddies farmed naturally for >8 years had less planthopper damage than conventional paddies, slightly lower densities of white-backed planthopper, much lower densities of brown planthopper, and higher rates of planthopper parasitism by the nematode Agamermis unka. Nematode density and parasitism showed a close correlation with variation in planthopper populations, suggesting that nematodes may control planthoppers in naturally farmed paddies.

Improving rice production sustainability by reducing water demand and greenhouse gas emissions with biodegradable films

In China, rice production is facing unprecedented challenges, including the increasing demand, looming water crisis and on-going climate change. Thus, producing more rice at lower environmental cost is required for future development, i.e., the use of less water and the production of fewer greenhouse gas (GHG) per unit of rice. Ground cover rice production systems (GCRPSs) could potentially address these concerns, although no studies have systematically and simultaneously evaluated the benefits of GCRPS regarding yields and considering water use and GHG emissions. This study reports the results of a 2-year study comparing conventional paddy and various GCRPS practices. Relative to conventional paddy, GCRPSs had greater rice yields and nitrogen use efficiencies (8.5% and 70%, respectively), required less irrigation (−64%) and resulted in less total CH4 and N2O emissions (−54%). On average, annual emission factors of N2O were 1.67% and 2.00% for conventional paddy and GCRPS, respectively. A cost-benefit analysis considering yields, GHG emissions, water demand and labor and mulching costs indicated GCRPSs are an environmentally and economically profitable technology. Furthermore, substituting the polyethylene film with a biodegradable film resulted in comparable benefits of yield and climate. Overall, GCRPSs, particularly with biodegradable films, provide a promising solution for farmers to secure or even increase yields while reducing the environmental footprint.

Efisiensi Sistem Irigasi Pipa untuk Mengidentifikasi Tingkat Kelayakan Pemberian Air dalam Pengelolaan Air Irigasi

Kehilangan air irigasi yang umum terjadi pada suatu areal pertanian selama pemberian air adalah aliran permukaan dan perkolasi yang keluar dari daerah perakaran. Irigasi pipa yang memiliki efisiensi mencapai 98% karena dapat mengontrol pemakaian air sesuai kebutuhan dan tidak ada terjadi rembesan selama penyaluran air. Jarak inlet petak sawah juga harus diperhatikan selain faktor teknologi irigasi. Jarak inlet petak sawah berpengaruh terhadap penyebaran air dalam suatu petakan sawah karena terkait dengan efisiensi aplikasi (Ea) dan efisiensi distribusi air (Ed). Metode yang digunakan pada penelitian ini yaitu metode deskriptif yang mengumpulkan data primer dan data sekunder. Selanjutnya pembuatan petak percoban yang telah dipasang irigasi pipa. Hasil penelitian menunjukkan nilai Ed di atas 90% pada perlakuan pemberian air konvensional dan System of Rice Intensification (SRI). Hal ini menjelaskan distribusi air pada teknologi irigasi pipa merata keseluruh areal tanam. Nilai Ea pada petak percobaan berkisar antara 76% - 98%. Perlakuan pemberian air konvensional nilai Ea lebih rendah dibandingkan dengan SRI. Hal ini dikarenakan air pada sawah konvensional terjadi perkolasi sehingga air keluar dari zona perakaran serta terjadinya aliran permukaan menyebabkan penurunan efisiensi. Hasil simulasi jarak inlet petak sawah menunjukkan bahwa Ea yang baik (≥ 90%) didapat pada jarak 30 m dengan sistem pemberian air secara SRI akan lebih hemat 10,25%. Tingkat kelayakan pemberian air berdasarkan nilai Ea diperoleh dari tingkat pola pemberian air irigasi pada sawah konvensional fase vegetatif kritis pada jarak 170 m, sedang fase generatif pada jarak 75 m menjadi kritis dan pada jarak 178 m menjadi sangat kritis. Petak sawah SRI menunjukkan nilai kelayakan pemberian air fase vegetatif mendekati kritis pada jarak 170 m, sedangkan fase generatif telah kritis pada jarak 150 m.

Modifying rice crop management to ease water constraints with increased productivity, environmental benefits, and climate-resilience

Water scarcity increasingly constrains agricultural production, particularly for rice, one of our most important food crops. Conventional paddy production is the world’s largest single consumer of water. Making certain changes in current cultivation practices, as discussed here, can raise rice crop yields while reducing water and other inputs. Diminished greenhouse gas (GHG) emissions, less runoff water pollution, and more climate-resilience are additional benefits. Spreading such changes in crop and water management within the rice sector can be a cost-effective response to agricultural water shortages, offering improvement in food security, adaptability to climate change, and environmental sustainability.

Canopy scale CO2 exchange and productivity of transplanted paddy and direct seeded rainfed rice production systems in S. Korea

Rice (Oryza sativa L.) is a primary food crop that supports more than half the world population. Paddy rice accounts for more than 75% of the total global rice production but requires large amounts of water for irrigation. Increasing water scarcity, however, raises concerns regarding the sustainability of paddy rice production and highlights the need for alternative approaches. Improved rice varieties that require less water, are drought tolerant and which can be directly seeded offer promising alternatives. In this study, we evaluated the performance of an improved rice variety (Oryza sativa subsp. Japonica cv. Unkwang) grown under direct seeding and rainfed cultivation. Aboveground biomass and leaf area development were measured every month by destructive harvesting. Canopy net ecosystem CO2 exchange (NEE) and ecosystem respiration (Reco) were measured using chambers. Gross primary production (GPP) was calculated from NEE and Reco. The maximum green leaf area index (GLAI) attained under rainfed agriculture was 4.9±0.5m2m−2 compared to 5.4±1.1m2m−2 in the conventional paddy rice production system. The respective peak total aboveground biomasses were 2.16±0.28 and 1.85±0.27kgm−2 while the corresponding grain weights were 1.19±0.10kgm−2 and 1.16±0.09, amounting to total yields of 6.61±0.22 and 5.99±0.68t/ha−1 for paddy and rainfed rice, respectively. The maximum daily cumulative GPP were 11.1 and 12.0gCm−2d−1, respectively, occurring at peak season, corresponding to maximum photosynthetic active radiation (PAR) and GLAI. On a daily basis, PAR explained >82% of the daily fluctuations in GPP while >90% of the seasonal changes in GPP were due to changes in GLAI and light use efficiency (α). Higher α in rainfed rice was attributed to higher leaf nitrogen (N) content. With adequate soil moisture supply, the Unkwang variety demonstrated the potential to grow under rainfed agriculture with comparatively good amount of yield. Since direct seeding, as in rainfed agriculture, eliminates the need for prior flooding of plots, it maximizes the use of early rainfall, which could be a water saving strategy and a reason to promote the introduction of Unkwang variety in the paddy rice-dominated Asian farming system.

Effects of land use conversion and fertilization on CH4 and N2O fluxes from typical hilly red soil.

Land use conversion and fertilization have been widely reported to be important managements affecting the exchanges of greenhouse gases between soil and atmosphere. For comprehensive assessment of methane (CH4) and nitrous oxide (N2O) fluxes from hilly red soil induced by land use conversion and fertilization, a 14-month continuous field measurement was conducted on the newly converted citrus orchard plots with fertilization (OF) and without fertilization (ONF) and the conventional paddy plots with fertilization (PF) and without fertilization (PNF). Our results showed that land use conversion from paddy to orchard reduced the CH4 fluxes at the expense of increasing the N2O fluxes. Furthermore, fertilization significantly decreased the CH4 fluxes from paddy soils in the second stage after conversion, but it failed to affect the CH4 fluxes from orchard soils, whereas fertilizer applied to orchard and paddy increased soil N2O emissions by 68 and 113.9%, respectively. Thus, cumulative CH4 emissions from the OF were 100% lower, and N2O emissions were 421% higher than those from the PF. Although cumulative N2O emissions were stimulated in the newly converted orchard, the strong reduction of CH4 led to lower global warming potentials (GWPs) as compared to the paddy. Besides, fertilization in orchard increased GWPs but decreased GWPs of paddy soils. In addition, measurement of soil moisture, temperature, dissolved carbon contents (DOCs), and ammonia (NH4+-N) and nitrate (NO3--N) contents indicated a significant variation in soil properties and contributed to variations in soil CH4 and N2O fluxes. Results of this study suggest that land use conversion from paddy to orchard would benefit for reconciling greenhouse gas mitigation and citrus orchard cultivation would be a better agricultural system in the hilly red soils in terms of greenhouse gas emission. Moreover, selected fertilizer rate applied to paddy would lead to lower GWPs of CH4 and N2O. Nevertheless, more field measurements from newly converted orchard are highly needed to gain an insight into national and global accounting of CH4 and N2O emissions.

Study on the impact of the system of rice intensification in less water endowed areas of Tamil Nadu

System of rice intensification (SRI) is a novel method of rice cultivation based on a set of simple synergistic practices. They aim to change the management of rice plants and soil, water and nutrients that supports them in simple but specific ways. Success of SRI depends on strict adoption of its five major components viz., young seedlings with mat nursery, single seedling planting, square planting, alternate wetting and drying of irrigation management and mechanical weeder usage. Among the five components, raising young seedling in the mat nursery, planting single seedling and square planting are the most important components that paves the way for increasing the yield of rice crop in irrigated rice systems. Proponents of SRI have reported that the average rice yield with SRI can be doubled from the current average yield level and there exists potential to the tune of increasing the yield level by three to four times. An attempt was made to evaluate the impact of adoption of SRI practices on rice yields, its economics in rice cultivation and labour inputs based on field research conducted in Varahanadhi Sub Basin, Villupuram and Tiruvannamalai districts, Tamil Nadu State, India. Rice yields with SRI were higher than those under conventional paddy cultivation by 34.35 per cent and net returns were higher by 33.24 per cent. SRI adoption enabled farmers consistently to enhance rice yields, increase returns and save labour cost and enhance productivity with respect to the key inputs in terms of rice output per unit of seed, water and fertilizer. SRI promises to be a significant alternative not only for raising rice yields, but also for managing rice based farming in wet lands ecosystem.

NITROGEN UPTAKE OF SRI PADDY FIELD COMPARE TO CONVENTIONAL FIELD

The aim of this research is to compare nitrogen uptake in SRI field and conventional paddy field. Three SRI plots and three conventional plots were given same amount of organic fertilizer and three different biochar amount. In SRI field, S1 were plot with 5 ton/ha biochar application, S2 were plot with 10 ton/ha biochar application, and S3 were plot with 20 ton/ha biochar application. Similarly, in conventional paddy field, K1, K2, and K3 were plots with 5 ton/ha, 10 ton/ha, and 20 ton/ha biochar application. Mineral fertilizer were not used in this research. Result shows that, Nitrogen uptake in SRI paddy field (average of 262.9 mg/g Dry mass) were less than Conventional paddy field (average of 323.8 mg/g Dry mass). However, average of the grain weight of 1000 paddy grain shows that grain from SRI field is heavier (average of 20.7 g) than conventional paddy field (average of 19.0 g). Biochar application of 5 ton/ha, for both SRI and conventional fields shows higher result in most of plant parameters (plant height, amount of grain, total weight). SRI method usually shows the high production compare to conventional method. However, in this experiment there is almost no difference in SRI field (3.6 ton/ha) and conventional field (3.7 ton/ha). Plant observation shows that SRI paddy develop good rooting system than conventional paddy field that implies on more nutrient uptake. Soil were suspected to be the cause of low nitrogen uptake in SRI field.

圃場整備済み水田における魚類保全を目指した江の創出手法の検討

圃場整備済み水田における魚類保全を目指した江の創出手法の検討

N2O-N Emissions from Organic and Conventional Paddy Fields from Central Java, Indonesia

To evaluate the effect of farming system on gaseous emission of N from soil, the measurements of nitrous oxide (N2O) were taken in organic and conventional paddy fields in tropics. Eleven soil samples from organic and neighboring conventional sites in Central Java, Indonesia were incubated at two different moisture contents expressed as water filled pores (WFPS), namely 75% WFPS and 100% WFPS. Emission of N2O-N at 75% WFPS was significantly higher in conventional management than in organic management. At 100% WFPS, the N2O-N emission was also higher in conventional than in organic farming system. Although it was not significantly different, it has significantly and positively correlations with SOC, total N and initial mineral N content. Due to the swelling ability of the high clay which is contained in soil samples, less N2O-N emission in 75% WFPS than in 100% WFPS was observed in the present study. The range of N2O-N emission at 75% WFPS was 0.01 – 0.03kg N2O-N/ha in organic farming and 0.005 – 0.16kg N2O-N/ha in conventional farming; for organic farming at 100% WFPS, the N2O-N emission was 0.04 – 61kg N2O-N/ha and in conventional farming was 0.08 – 74kg N2O-N/ha. This study concludes that organic farming in paddy fields might have more promising potential to mitigate N2O-N emission than conventional farming in paddy fields.

Indirect effects of nutrients in organic and conventional paddy field soils on the rice grasshopper, Oxya japonica (Orthoptera: Acrididae), mediated by rice plant nutrients

Current agricultural technology depends on synthetic fertilizers and enhances the growth of herbivorous insect populations. Some organic farming uses bio-based nutrients instead and is considered the most promising way to mitigate the negative effects of conventional farming. The rice grasshopper Oxya japonica (Thunberg) (Orthoptera: Acrididae) is the most abundant herbivore in both conventional and organic fields in northern Japan. This study investigated the effects of soil nutrients associated with conventional versus organic farming on rice plant quality,and the growth and performance of O. japonica in paddy fields at Sakata, Yamagata Prefecture. A laboratory experiment was also conducted to understand the effects, as mediated by host plant quality, of organic and conventional soil nutrients on the growth and feeding (as measured by the leaf area consumed) of O. japonica. Nymphs of O. japonica that fed on nitrogen-rich, carbon-poor plants cultivated in conventional soil grew and developed faster than those feeding on organic plants. The rice plants in conventional fields had greater biomasses, suggesting that they were more likely to tolerate grasshopper damage. These results support the importance of soil nutrient management as a factor that influences plant–herbivore interactions.