Do rates matter? Validation of insect frass fertilizer rates in a vegetable intensified push-pull technology for optimal sustainable production

SUMMARYLong-term fertilization experiment has been conducted since 1981 to study the effect of soil management practices on soil fertility, soil carbon and nitrogen sequestration, soil culturable microbe counts and crop yields at the Nanhu Experimental Station in the Hubei Academy of Agricultural Sciences (situated in the middle reach of the Yangtze River and the rice–wheat cropping system). The experiment was designed with the following eight treatments: (1) unfertilized treatment: Control; (2) inorganic nitrogen fertilizer treatment: N; (3) inorganic nitrogen plus inorganic phosphorus fertilizer treatment: NP; (4) inorganic nitrogen, inorganic phosphorus plus inorganic potassium fertilizer treatment: NPK; (5) pig dung compost (manure) treatment: M; (6) inorganic nitrogen fertilizer plus manure: NM; (7) inorganic nitrogen, inorganic phosphorus fertilizer plus manure treatment: NPM and (8) inorganic nitrogen, inorganic phosphorus, inorganic potassium fertilizer plus manure treatment: NPKM. The results showed that long-term application of organic manure in combination with inorganic fertilizer significantly (p< 0.05) increased soil organic C concentrations compared with the corresponding inorganic fertilizers alone. Soil organic C contents were significantly (p< 0.05) increased in balanced application of NPK fertilizers in comparison to unbalanced application of fertilizers. After 30 years of experiment, soil organic C and total N sequestration rate averagely were 0.48 t ha−1year−1and 28.3 kg ha−1year−1in the fertilized treatments respectively; nevertheless, it were 0.27 t ha−1year−1and 9.7 kg ha−1year−1in the unfertilized treatment. Application of organic fertilizer in combination with inorganic fertilizer significantly (p< 0.05) increased culturable microbial counts compared with the corresponding inorganic fertilizers alone. The balanced application of NPK fertilizers significantly (p< 0.05) increased culturable microbial counts compared with unbalanced application of fertilizers. The average grain yield of wheat and rice was significantly (p< 0.05) higher in organic manure combined with inorganic fertilizer treatment than in inorganic fertilizer alone and unfertilized control. Therefore, long-term application of organic manure combined with inorganic fertilizer and balanced application of NPK fertilizers could increase soil organic C and total N sequestration, culturable microbial counts and crop grain yields.

Ammonia-oxidizing archaea and bacteria (AOA and AOB, respectively) are important intermediate links in the nitrogen cycle. Apart from the AOA and AOB communities in soil, we further investigated co-occurrence patterns and microbial assembly processes subjected to inorganic and organic fertilizer treatments for over 35 years. The amoA copy numbers and AOA and AOB communities were found to be similar for the CK and organic fertilizer treatments. Inorganic fertilizers decreased the AOA gene copy numbers by 0.75–0.93-fold and increased the AOB gene copy numbers by 1.89–3.32-fold compared to those of the CK treatment. The inorganic fertilizer increased Nitrososphaera and Nitrosospira. The predominant bacteria in organic fertilizer was Nitrosomonadales. Furthermore, the inorganic fertilizer increased the complexity of the co-occurrence pattern of AOA and decreased the complexity pattern of AOB comparing with organic fertilizer. Different fertilizer had an insignificant effect on the microbial assembly process of AOA. However, great difference exists in the AOB community assembly process: deterministic process dominated in organic fertilizer treatment and stochastic processes dominated in inorganic fertilizer treatment, respectively. Redundancy analysis indicated that the soil pH, NO3−N, and available phosphorus contents were the main factors affecting the changes in the AOA and AOB communities. Overall, this findings expanded our knowledge concerning AOA and AOB, and ammonia‐oxidizing microorganisms were more disturbed by inorganic fertilizers than organic fertilizers.

The diversity of insects, both pests and natural enemies in each place differently is influenced by environmental factors and technical culture of cultivation. This study aims to determine the diversity of pests and natural enemies in nutmeg plants in South Aceh. Insect sampling was carried out at nutmeg plantations in South Aceh, followed by identification in the Faculty of Agriculture laboratory, Teuku Umar University. Methods of data collection using purposive sampling, using light traps, pit fall traps, yellow traps. The Parameters of this study are number of individuals, families, and insect diversity obtained. The results showed that the abundance of pests and natural enemies in Meukek was higher compared to Samadua. The Shannon-Wiener index shows a variety of pests in Meukek high (H'=3.029) and moderate in Samadua (H'=2,788). While the diversity of natural enemies in both Meukek and Samadua is relatively low, namely H'= 1.230 and H' = 1.049. Planting patterns and crop management affect the abundance and diversity of both pests and natural enemies in both locations. Plantations in Meukek tend to be heterogeneous which are planted with a variety of plantation crops (polyculture) while nutmeg plants in the same two are relatively homogeneous (monoculture of nutmeg). Keywords: diversity, pests, parasitoids, predators, nutmeg

Insects in agricultural ecosystem can play a role as pests or natural enemies. The abundance and diversity of insect pests and natural enemies are interconnected because insect pests are food for natural enemy insects. The aims of the study were to compare the abundance and diversity of pest insects and natural enemies of corn and rice plant, and to determine the similarity of pest insects and natural enemies of corn and rice plant using crop rotation systems. The sampling has performed four times i.e, in the vegetative phase of corn, generative corn, vegetative rice, and generative rice. The sampling method used sweep net method. The results showed that the number of individual pest insects and natural enemies of each growth phase of corn plants were lower than rice plants. The number of species pest insect and natural enemies of each growth phase of corn plants were lower than rice plants. In addition the diversity of pest insect of each growth phase of corn plants was higher than rice plants while the diversity of natural enemies in each growth phase of corn plants was lower than rice plants. The diversity index of pest insects and natural enemies of each growth phase in corn plants and rice plants was in the medium category. The presence of pest insects and natural enemies in each growth phase of corn and rice plants shows the species in the two compared ecosystems were different.

Insects in agricultural ecosystem can play a role as pests or natural enemies. The abundance and diversity of insect pests and natural enemies are interconnected because insect pests are food for natural enemy insects. The aims of the study were to compare the abundance and diversity of pest insects and natural enemies of corn and rice plant, and to determine the similarity of pest insects and natural enemies of corn and rice plant using crop rotation systems. The sampling has performed four times i.e, in the vegetative phase of corn, generative corn, vegetative rice, and generative rice. The sampling method used sweep net method. The results showed that the number of individual pest insects and natural enemies of each growth phase of corn plants were lower than rice plants. The number of species pest insect and natural enemies of each growth phase of corn plants were lower than rice plants. In addition the diversity of pest insect of each growth phase of corn plants was higher than rice plants while the diversity of natural enemies in each growth phase of corn plants was lower than rice plants. The diversity index of pest insects and natural enemies of each growth phase in corn plants and rice plants was in the medium category. The presence of pest insects and natural enemies in each growth phase of corn and rice plants shows the species in the two compared ecosystems were different.

Effects of rice straw and nitrogen fertilization on greenhouse gas emissions and carbon storage in tropical flooded soil planted with rice

Crop pests are a permanent threat to horticultural production. Several control methods are recommended for their control, including biological control. This method based on the use of natural enemies is not well established. The objective of this study was to assess the diversity and abundance of natural enemies of crop pests. A survey of crops associated with pests was carried out on 144 fields in southern Senegal to measure the diversity and abundance of natural enemies of various crop pests, determine the native parasitoid complex and assess parasitism rates. Ecological indices were calculated to assess the diversity of natural enemies. A total of 25 natural enemy species were identified, including 15 parasitoids and 10 predators. Predatory Hemiptera and Parasitoid Hymenoptera were high biodiversity. The parasitism rates vary between 0 and 50% depending on the abundance of pests and parasitoid species. Knowledge of the diversity of natural enemies and the understanding of trophic interactions with pests are important in the development of biological crop protection in order to preserve resilience in agroecosystems.

Minna Padi is an integrated rice fish farming system that implements environmentally friendly cultivation and creates a sustainable ecosystem. However, the effects of minna padi farming systems on the diversity of natural enemies have not been reported previously. This research was conducted to compare the diversity and abundance of natural enemies [parasitoids and predators] in minna padi and conventional rice fields. Three pairs of minna padi and conventional paddy fields were selected for fields research. Natural enemies were collected in the field research using sweeping nets, yellow sticky traps and pitfall trap every two weeks during the cultivation. The results showed that the abundance of parasitoids was higher in minna padi than that in conventional farming systems. However, the abundance of predators was higher in conventional farming systems. Parasitoid and predator species richness also showed no difference between the two rice farming systems. However, the composition between the two farming systems was different, minna padi was dominated by parasitoids such as Aphonagmus sp. and Eurythoma dentata, while conventional dominated by a predator such as Pardosa pseudoannulata and Plexippus sp.

Wildflower strips sown at field margins can attract and support natural enemies required for conservation biological control of insect pests in agroecosystems. By focusing on perennial flowering strips, the present review discusses ways to compose flower mixtures that attract and support a high abundance and diversity of flower-visiting natural enemies. It firstly recalls why a high abundance and diversity of natural enemies is needed to enhance biological control. Thereafter, This review describes and discusses the approach consisting of picking and mixing flower species to compose mixtures. In past research, an array of flowers has been screened in various experimental conditions to select those attracting and supporting natural enemies. These results helped to develop mixtures that have been sown in fields. Although these mixtures often succeeded in increasing the abundance of some natural enemies (e.g., zoophagous hoverflies (Diptera: Syrphidae)), they often failed in enhancing a high diversity of predators and parasitoids simultaneously. A better understanding of flower-natural enemy interactions has been possible by screening the effects of functional flower traits on insect behavior. These results, here reviewed, notably revealed that distinct natural enemies may respond to different values of a given trait. It led to hypothesize that a high functional diversity of mixtures should attract and support a high diversity of natural enemies. The results from field-based research showed that increasing functional diversity per se may not be the key to enhance natural enemy diversity in wildflower strips. Hence, we propose here that a tailored functional diversity, consisting of picking and mixing the functional trait values known to attract and support a high variety of natural enemy species, could guide the composing of flower mixtures.

Soil nutrients depletion directly threatens sustainability of food systems by reducing agricultural productivity, degrading ecosystem services, thus increasing the need for external inputs. Frass, a nutrient-rich byproduct of insect farming, is increasingly recognized for its potential in sustainable agriculture. In the current study, we explored the effects of composted Black Soldier Fly (BSF) frass on the growth and yield of Solanum macrocarpon (African eggplant) and Lactuca sativa (Lettuce), as well as its effect on soil nutrient composition, compared to poultry manure and inorganic fertilizers (NPK and urea). Two field experiments were conducted separately for lettuce and the African eggplants, each involving six treatments and four replicates per crop species. For lettuce, treatments included: BSF frass at 20 t/ha (T1), poultry manure at 20 t/ha (T2), BSF frass at 20 t/ha + 100 kg/ha urea (T3), BSF frass at 10 t/ha + 100 kg/ha urea (T4), NPK (15:15:15) at 200 kg/ha + 100 kg/ha urea as positive control (T01), and unfertilized soil as negative control (T0). For African eggplant, treatments consisted of: BSF frass at 15 t/ha (T1), 10 t/ha (T2), and 5 t/ha (T3), poultry manure at 10 t/ha (T4), NPK (15:15:15) at 200 kg/ha + 100 kg/ha urea as positive control (T01), and unfertilized soil as negative control (T0). Plant growth parameters like plant height, number and size of leaves and yield were analyzed. The results showed that, BSF frass at 20t/ha and 10t/ha significantly performed better than the other fertilizers in promoting plant growth and increasing yield in lettuce (3.53 kg per 3m2 and 5.12 kg per 3m2 in season 1 and 2, respectively) and of the African eggplant (5.04 kg per m2). Yield improvements reached approximately 50% compared with inorganic fertilizer treatments. Post-harvest soil analysis showed significant differences among treatments for African eggplant in nitrogen (N), phosphorus (P), potassium (K), and electrical conductivity (EC), while for lettuce, only soil pH differed significantly. These findings suggest that BSF frass is a viable alternative to both inorganic and organic fertilizers, offering a sustainable solution for improving crop productivity and soil health.

Management practices, including use of organic and inorganic fertilizers, significantly affect soil organic carbon (SOC) pool and agronomic yield. Crop yields in semi-arid regions of Turkey are declining because of depletion of SOC pool and the attendant decline in soil quality. Thus, this study was conducted to assess the effects of inorganic and organic fertilizer treatments (control, chemical fertilizer, animal manure, compost and compost + mycorrhizal inoculation) on SOC pool and agronomic yield in a long-term field experiment initiated in 1996 on the Mediterranean coast of Turkey. The SOC pool under different soil fertilizer management treatments was related to agronomic yield of pepper, wheat and maize. Biomass production increased as the SOC concentration increased with the application of organic and mineral (inorganic) fertilizers compared with the control. Between 1996 and 2010, the SOC concentration in 0-15 cm depth of the unfertilized control decreased from 0.96% to 0.87%. In comparison, SOC concentration increased in treatments amended with organic fertilizers such as manure, compost and compost+mycorrhzae. Agronomic yield was also significantly affected by Original Research Article American Journal of Experimental Agriculture, 4(9): 1086-1102, 2014 1087 organic and inorganic fertilizer treatments, which declined over time in the control but increased in treatments receiving compost, manure and compost + mycorrhizae. The negative regression was obtained in control treatments between SOC and the wheat yield (Y = -1.18x + 3.84, R=0.205) and maize yield (Y = -1.28x + 7.56, R=0.016). Additional research is needed to assess the role of fertilizers on SOC concentration and its effects on agronomic yields under long-term soil and crop management systems especially with mycorrhizal inoculation.

Recent studies have suggested that best management practices, such as dietary modification, used to reduce phosphorus (P) in litter may increase P runoff from pastures fertilized with litter. The objective of this study was to determine the effects on soluble P, Mehlich 3 P, Morgan P,or Olsen P with time as the result of fertilization, using litter from dietary modification and from litter amendment treatments. Poultry litter and inorganic fertilizer additions to high and low soil test P (soil test phosphorus, STP) soils resulted in an increase in all P fractions as compared with unfertilized soil. Soluble P in soils increased until about week 4 or 8 after additions of poultry litter. There were no appreciable changes in Mehlich 3 P with time in high STP soil; however, there were significant decreases in Mehlich 3 P when low STP soils were fertilized with poultry litter and inorganic fertilizer. Use of dietary modification (phytase and/or HAP corn) tended to cause slight to moderate reductions in extractable P compared with a normal diet, whereas addition of alum to poultry litter tended to result in significant reductions in the various P fractions analyzed. The P sorption ratio (phosphorus sorption ratio, PSR) was also increased by inorganic and poultry litter fertilizer treatments, although in both high and low STP soil, use of HAP corn, phytase, and alum resulted in similar PSR values compared with unfertilized soils. Results from this study indicate that poultry producers should use dietary modification and alum to maximize the ability of their soils to receive poultry litter as a valuable fertilizer resource.

The diversity of the arthropod fauna in apple orchards in Central Otago was recorded from 1994 to 1999 using beating trays, pitfall traps, and sticky traps and the data analysed by the Shannon–Wiener Index. Three different fruit production systems were compared, conventional (CFP), integrated (IFP), and biological (BFP), to determine whether total arthropod diversity and/or the diversity of natural enemies (predators and parasitoids) could be used to measure the sustainability of their pest management practices. The contribution of natural enemies to the diversity indices was also examined to determine if they reflected the key species essential for sustainable pest management. The diversity of natural enemies in beating trays was found to be the measure most sensitive to changes in pest management. The diversity of both the total arthropod fauna and natural enemies was much lower under CFP than under either IFP or BFP, due to the use of broad-spectrum pesticides. This practice made the CFP programme unsustainable and it is no longer used. During the transition from CFP to IFP, the diversity indices rose to become similar to that in the BFP programme by the third season. The introduction of frequent applications of fungicides in BFP, including lime sulphur, appeared to reduce total arthropod and natural enemy diversity. Falls in the diversity indices for natural enemies were shown to reflect reduced numbers, range, and evenness of natural enemies but not necessarily the key species known to be critical for sustainable pest management. It is proposed that a Shannon–Wiener Index for natural enemies in beating trays of 0.2 or less in summer is strongly indicative of unsustainable pest management in Otago apple orchards. On the other hand, indices of 0.3–0.8, as found under IFP and BFP, do not give unequivocal or quantitative indications of the sustainability of pest management. A suite of other measures of sustainability are more useful, notably combining lower pesticide use, reduced pest damage and presence at harvest, the greater roles of key natural enemies, more effective plant resistance to pests and diseases, and higher profitability.

Intercropping is one of the polyculture crop cultivation techniques. Polyculture cropping system can increase the diversity of insects. This research aims to determine the effect of different plant composition of soybean and corn on the diversity and abundance of natural enemies. This research was carried out using a single factor experimental method arranged in a single plot field design. The treatment tested was the plant composition of soybean and corn which consisted of 4 compositions setting as treatment i.e., 2:1, 3:1. 4:1 and 5:1. In addition, monoculture soybeans and monoculture corn were also planted for comparison. Observation and sampling of natural enemies were carried out using insect sweeping net, yellow pan trap, and pitfall trap. Samplings were done 7 times when the plant at 2, 3, 4, 6, 8, 10, and 12 weeks old. The results showed that the plant composition of soybean and corn affected the number of species and abundance of insect natural enemies. Nonmetric multidimensional scale analysis shows that there are less differences in the composition of insect natural enemies between different plant compositions.

Pests are one of the limiting factors in increasing soybean production. Pest control carried out by farmers using pesticides is feared to threaten the sustainability of soybean production in Indonesia. This study aimed to identify the effect of different pest management systems and various soybean varieties on pest population dynamics, abundance and diversity of natural enemies, plant damage, and soybean production. A split plot design with three replications was applied, where the main plot was pest management systems i.e. (1) control (which received neither chemicals nor integrated pest management), (2) chemical control, and (3) integrated pest management, and the sub-plot was soybean varieties i.e. (1) Anjasmoro, (2) Demas 1, and (3) Dering 1. Results indicated that variety affects pest diversity and abundance, however, it affected leaf damage, pod damage, and production. The pest management systems influenced the diversity and abundance of pests and natural enemies, plant damage, and production. Interaction between variety and pest management system affected plant damage. We conclude that the use of resistant varieties combined with integrated pest management could reduce plant damage, maintain the natural enemy population, and optimize soybean production.