The application of several bioameliorant formulations to increase soil nutrient concentration and yields maize-soybeans intercropping flexible to climate change in suboptimal land North Lombok, Indonesia

Many maize and soybean plants are planted with an intercropping system on suboptimal land in North Lombok. However, this plant is sensitive to climate change, drought stress, and soil fertility. This study is aimed at determining the increased soil nutrient concentrations and yields in several applications of bioameliorant in maize and soybean intercropping on suboptimal land in North Lombok. A randomized block design was utilized for the experiment, and the five treatments for the bioameliorant formulation were F0: without bioameliorant, Formulas F1 and F2 for bioameliorants contain 10% compost, 10% cattle manure, 10% rice husk charcoal, and 70% mycorrhizal biofertilizer, 55% mycorrhizal biofertilizer plus 15% compost plus 15% cattle manure plus 15% charcoal husk, F3: bioameliorant composition comprising 40% mycorrhizal biofertilizer, 20% compost, 20% cattle manure, and 20% rice husk charcoal, 25% compost, 25% cattle manure, 25% rice husk charcoal, and 25% mycorrhizal biofertilizer make up the bioameliorant composition F4. The results showed that the number of mycorrhizal spores in the soil, the percentage of infected roots, the yield of maize and soybean intercropping, and the concentration of N, P, and K nutrients can all be increased by the bioameliorant formulation of 25% compost + 25% cattle manure + 25% rice husk charcoal + 25% mycorrhizal biofertilizer.


Introduction
North Lombok has a suboptimal land area of 38,000 ha which has the potential for cultivating several food crops [1].However, only 30% of this area is used for food crops such as maize and soybeans which are planted in intercropping.This suboptimal land is characterized by a dry climate (classified as E and F climates according to Schmidt and Ferguson) [2], soil fertility and low water availability (very low total N, low available P, very low available K and very low organic C) [3].Conditions like this can cause crop failure, low crop productivity and sensitivity to climate change [4].
However, the use of suboptimal land is faced with soil structure constraints which are dominated by 70% sand particles, which is porous so that it becomes a soil biophysical and chemical constraint [5].This condition is exacerbated by the high permeability of the soil, which is sensitive to erosion and has a low cation exchange capacity.One of the efforts to increase the productivity of sandy soil is by adding 1253 (2023) 012036 IOP Publishing doi:10.1088/1755-1315/1253/1/012036 2 bioameliorant to improve the physical, chemical and biological properties of the soil, including using manure, compost and rice husk charcoal enriched with mycorrhizal biofertilizers [6].Manure and compost materials can improve soil pores and soil aggregates so that soil drainage and the ability of roots to absorb nutrients increases.The application of manure and compost as organic fertilizer also plays an active role in increasing the N content in the soil.Decomposition and mineralization of manure and compost is able to meet the N needs of plants [7].Manure, rice husk charcoal and compost are good organic matter constituents that can improve soil physical properties [8].One way to improve these physical properties is through a decrease in total porosity and an increase in the density of lumps in the soil which can have an impact on the uptake of nutrient P.Meanwhile, rice husk charcoal is a porous black substance with a high C content formed due to incomplete combustion or pyrolysis of biomass in the form of rice husks charcoal [9].Rice charcoal husk has a lot of pore space so that it functions as a store of nutrients which will slowly be released into the soil [10].Additionally, the increase in C-organic and mycorrhizal activity in the soil is directly correlated with the treatment of ameliorants that contain a lot of organic matter [11].Because it can supply the vital components needed for mycorrhizal to develop, enough organic matter in the soil acts as a source of energy for the growth of mycorrhiza [12].Mycorrhizae and plants can symbiotically promote plant growth by increasing phosphorus nutrient intake [13,14].
However, how much the application of several bioameliorant formulations can increase soil nutrient concentrations and yields of intercropped maize and soybeans that are flexible to climate change in suboptimal land of North Lombok has not been revealed much.This study aims to determine the increase in soil nutrient concentrations and yields in several applications of bioameliorant formulations in maize and soybean intercropping.

Conduct of experiments
To get weeds out of the soil, a tractor is used for tillage.Three seeds were placed in each hole, with a maize spacing of 60 cm by 40 cm and a soybean spacing of 30 cm by 20 cm.Replanting maize and soybean seeds seven days after planting (dap) allows for stitching, which replaces plants that die or grow abnormally.Provision of bioameliorant in accordance with the treatment of each bioameliorant formulation with a dose of 40 g per hole, 5 cm away from the planting hole, 7 cm deep.While Urea and Phonska are applied at a rate of 50% of the recommended dosage for inorganic fertilizers (soybeans: 30 kg/ha Urea and 60 kg/ha Phonska; maize: 150 kg/ha Urea and 100 kg/ha Phonska).Bioameliorant was applied at the time of planting; 50% inorganic fertilizer I was applied to maize and soybeans seven days after planting (dap), and 50% inorganic fertilizer II was applied twenty-one days after planting.
When the plants are 10 dap old, they must be cleaned of any weeds that have grown.Thereafter, weeding must be done every 7 days until the plants are 50 days old.At the ages of 30 and 50 days, water is delivered from pump wells if the amount of rainfall in the field is insufficient to meet the needs of the plants.

Observation of variable
In this investigation, the following variables were observed: (1) soil nutrient concentration variables (N, P, K), C-organic and soil pH at 42 and 92 dap and plant nutrient uptake (N, P, K, Ca) at 42 dap, (2) mycorrhizal population variables: number of spores and percentage of root infection at 42 dap and 92 dap, and (3) crop yield variables: harvested dry stover weight, dried stover weight, dried cob and pod weight, 100 grain weight and dry shelled weight.

Plant nutrient uptake and soil nutrient concentration
When compared to other formulation treatments, the results of the analysis of variance revealed that the bioameliorant formulation treatment of 25% compost + 25% cattle manure + 25% rice husk charcoal + 25% mycorrhizal biofertilizer had a significant impact on soil nutrient concentrations and nutrient uptake by plants (Tables 1 and 2).
Table 1.Concentrations of soil nutrients (N, P, and K), organic matter (C-organic), and soil pH in the treatment of bioameliorant formulations for maize and soybean intercropping that were aged 42 and 92 dap.
Bioameli orant N (g kg -1 ) P (mg kg -1 ) K (cmol kg -1 ) C-organic (g kg Application of bioameliorant formulation 25% compost plus 25% cattle manure, husk charcoal at a ratio of 25% plus 25% mycorrhizal biofertilizer in dose 25 tons per hectare revealed the concentration of soil N and P nutrients, and NP uptake in plants revealed notable variations in both the soil and shoot.The chemical and physical characteristics of sandy soil can be enhanced by the application of this bioameliorant mixture [15].A decrease in total porosity and an increase in particle density in sandy soils are two ways that physical qualities might be improved that may have an effect on increased nutrient uptake, particularly P [16] The uptake of P by plant roots is also impacted by changes in soil pH.Because P is immobile, P absorption will be disrupted at low pH levels [17].The growth and function of roots are also interfered with by this situation.P supply from bioameliorant and inorganic fertilizers can boost N and P uptake in maize plants [18].The maximum NPK nutrient uptake is achieved with a bioameliorant formulation of 20 tonnes ha -1 , which contains 80% chicken manure and 20% dolomite.This state is most likely caused by the bioameliorant formulation's ability to enhance the concentration of P that is readily available in the soil solution, increasing the amount of P that is available in the soil.The nutrients in the bioameliorant are also slow-releasing, making them continuously accessible and usable by plants [19].Cow dung, rice husk charcoal, compost, and mycorrhiza significantly boosted soil pH, N, P, K, and C-organic content, as well as N, P, K, and Ca nutrient uptake by maize and soybean plants grown on suboptimal land [20].Organic matter as an ameliorant can boost C-organic in the soil, allowing nutrients such as N, P, K, Ca, Mg, and S to be available for maize and soybean plants during growth and plant tissue formation [21].Suspected the planting medium has increased accessible P levels.In that case, this is because the majority of phosphorus in the soil originates from weathering of natural mineral rocks, with the remainder coming from weathering of organic mineral components.The phosphorus ions in the soil are similarly impacted by soil pH [22].

Development of mycorriza
The results revealed that the 25% compost + 25% cattle manure + 25% rice husk charcoal + 25% mycorrhizal biofertilizer treatment bioameliorant formulation treatment had a significant effect in comparison to other bioameliorant dose treatments on the parameters number of spores mycorrhizal and percentage root colonization at 42 and 92 dap (Table 3).
By application bioameliorant formulations into the soil, soil fertility can be improved physically, chemically, and biologically.Organic materials can supply nutrients to plants and have both macro and micro holes, which improve air circulation and increase water absorption.Increased activity and mycorrhiza populations in the rhizosphere were achieved with bioameliorant treatment using a combination of 25% compost + 25% bovine manure + 25% rice husk charcoal + 25% mycorrhizal biofertilizer (F4) as basic fertilizer.One activity that is highly helpful in absorbing plants' readily available P nutrients is a mycorrhizal activity in the soil.Mycorrhiza requires energy to carry out its functions and develop, and the organic elements in this bioameliorant formulation serve as a source of energy for the development of these mycorrhizae [23].Increases in soil C-organic content and mycorrhizal activity are directly correlated with the application of bioameliorants rich in organic matter [24].Because the organic material potential to increase the activity of mycorrhizal fungi in the soil, which can store and release nutrients for plants.To carry out their metabolic functions and to grow and develop, mycorrhizal fungi require specific organic substances as a source of carbon and nutrients [25].The addition of a bioameliorant can boost mycorrhizal effectiveness on plant root infection.Organic substrates provide energy to mycorrhizal fungi, whereas growth hormones, which are also found in organic matter, stimulate the growth and regeneration of plant roots and create root exudate, accelerating the symbiotic interaction between mycorrhizal fungi and plants [26].The ability of mycorrhizae to boost phosphorus nutrient uptake and enhance plant development is the primary benefit of the symbiosis between them and plants.By enhancing plant nutrition, mycorrhiza can promote plant growth and yield [27].

Plant yield
When compared to other bioameliorant formulation treatments, the results of the analysis of variance and the HSD test at the 5% level showed that the 25% compost + 25% cattle manure + 25% rice husk charcoal + 25% mycorrhizal biological fertilizer treatment significant impact on dry harvested stover weight, sun-dried stover weight, cob weight, and sun-dried maize and soybean pods per plot at 92 dap (Table 4).The weight of harvested dry shelled seeds (kg/plot) and the weight of 100 dry maize and soybean seeds (g) in several bioameliorant formulations aged 92 dap compared to other bioameliorant formulations were significantly affected Table 5.Based on Tables 4 and 5, the treatment of the bioameliorant formulation that contains 25% compost + 25% cattle manure + 25% husk charcoal + 25% mycorrhizal biofertilizer, weight of harvested dry stover, weight of dry roasted stover sun, weight of dry cobs maize and pods soybeans per plot, weight of harvested dry shelled seeds, and weight of 100 dry maize and soybean seeds is higher than other bioameliorant dose treatments.It is claimed that the composition of the bioameliorant, which consists is sufficient to good supply the nutrients N, P, and K. Physically, manure can enhance soil pores and soil aggregates to improve soil drainage and boost roots' capacity to absorb nutrients [28].The application of manure as organic fertilizer also plays an active role in increasing the N content in the soil so that the amount of N produced from the decomposition and mineralization of manure is able to meet the N needs of plants [29].The better the vegetative growth of the plant, the more the photosynthesis process will run well so that more photosynthates are produced.Photosynthesis results from the vegetative phase to the generative phase and will be stored as food reserves in the form of carbohydrates in the form of seeds.Cattle manure acts as a source of N, P, and K as well as other micronutrients and is biologically capable increase mycorrhizal population so as to support plant growth and development [30].Manurederived bioameliorant contributes to the characteristics of the soil by making it more friable, allowing air to enter, holding water and nutrients so that they are not washed away, and boosting the activity of soil microorganisms in suboptimal land [31].This bioameliorant's nutrient composition is categorized as having a high N, P, and K nutrient content so that plants can absorb it in appropriate amounts [32].After being absorbed by plants, the N element found in manure, rice husk charcoal, and compost becomes a component of organic matter in the leaves and seeds, increasing the dry weight of seeds when applied to plants [33].In addition to the element N, bioameliorant also contains a significant amount of the element P. Since P is necessary for floral development, seed filling, and seed enlargement, providing a high P tends to boost yields and climate change resistance [34].

Conclusion
The number of mycorrhizal spores in the soil, the percentage of infected roots, the yield of maize and soybean intercropping, and the concentration of N, P, and K nutrients can all be increased by the bioameliorant formulation of 25% compost + 25% cattle manure + 25% rice husk charcoal + 25% mycorrhizal biofertilizer.

Table 2 .
Concentrations of N, P, K, and Ca plant nutrient absorption in various bioameliorant formulations intercropped with maize and soybean aged 42 dap.

Table 3 .
Mean number of spores and mycorrhizal infection (per 100 g of soil) soybean maize intercropping on several the formulation of bioameliorants.

Table 4 .
Weight of Harvested Dry Stoves (WHDS), Weight of Sun Dry Stoves (WDS), Weight of Maize and Soybean Sun Dry Cobs and Pods (WCD/WPD) Per Plot at 92 dap.

Table 5 .
Weight of 100 dry maize and soybean seeds (g) in varied bioameliorant formulations aged 92 dap and weight of harvested dry shelled seeds (kg/plot).