DIAGNOSIS AND RECOMMENDATION INTEGRATED SYSTEM (DRIS) FOR EVALUATING NUTRIENT STATUS OF COTTON (GOSSIPIUM HIRSUTUM)

Diagnosis and Recommendation Integrated System (DRIS) approach was employed to monitor the nutrient status of cotton (Gossipium hirsutum) in southwestern districts of Punjab, North-West India. DRIS norms for macro, secondary and micro nutrients in cotton plant are developed. Considering these DRIS norms, the most limiting nutrient for cotton plant in the region is identified along with the order in which the other nutrients become limiting. The DRIS approach indicated that 11, 3, 8, 5, 2, 4, 2, 3, 6 and 2 percent of the total cotton leaf samples collected were low in nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu), respectively. Leaf tissues of cotton plant were also found to contain high to excessive content of N, P, K, Ca, Mg, S, Fe, Mn Zn and Cu in 11, 7, 15, 19, 25, 18, 66, 33, 9 and 25 percent samples, respectively. DRIS derived sufficiency concentration ranges obtained from survey of cotton fields in this region were 2.22 to 5.20% N, 0.20 to 0.47% P, 1.05 to 2.14% K, 1.66 to 2.86% Ca, 0.34 to 0.57% Mg, 0.65 to 1.11% S, 106 to 172 mg kg^?1 Fe, 35 to 68 mg kg^?1 Mn, 18 to 33 mg kg^?1 Zn, and 5 to 8 mg kg^?1 Cu. The results elucidate that DRIS technique can be used for macro, secondary and micro nutrients indexing of cotton crop irrespective of its cultivar.     

DRIS and geostatistics indices for nutritional diagnosis and enhanced yield of fertirrigated acai palm

Abstract

Information about Açaí palm (Euterpe oleracea Mart.) nutrition, that gives support for yield increase is sparse. The aim of this study was to assess the nutritional status of fertigated Açaí palm by the Index called Diagnosis and Recommendation Integrated System (DRIS), as well as the spatial variability of this Index and its productivity. We achieved a sampling of 80 geo-referenced points in an Açaí palm commercial crop area. Then we assessed the yield and contents of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. The DRIS evaluation indicated that the frequency of nutrients in suitable status was N?>?S?>?Zn?>?B>Fe?>?K>Ca?>?Mg?>?P>Mn?>?Cu, in deficiency was Mn?>?Ca >?B>Cu?>?Mg?>?Fe?>?K?>?P?>?S>Zn?>?N, and in excess was P?>?Cu?>?Mg?> K?>?N?=?Zn?>?Fe?>?Ca?>?S?=?B?>?Mn. The nutrients N and S were well balanced, whereas Mn, Ca and B were the nutrients with the highest frequency of deficiency. The sampling points were close enough to detect the spatial variability of DRIS Index. Thus, it was possible to observe the patterns for the nutritional deficiencies, occurring at the final part of the irrigation, as well as the variability of the Açaí palm yield. The spatial variability of the DRIS Index was efficient to indicate the points in which fittings in the fertilization doses are required.     

Monitoring Nutrient Status of Guava Fruit Trees in Punjab,Northwest India through the Diagnostic and Recommendation Integrated System Approach

Abstract

The Diagnostic and Recommendation Integrated System (DRIS) was employed for interpreting nutrient analyses of leaf tissue of guava fruit trees (Psidium guajava L.) cultivated in Punjab, northwest India. Standard reference DRIS norms were established for various nutrient ratios and used to compute DRIS indices, which assessed nutrient balance and order of limitation to yield. The DRIS evaluation and sufficiency range approach were equally effective and in agreement for diagnosing deficiencies of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), manganese (Mn), zinc (Zn), and copper (Cu). The results also show that the position of leaf tissue sampled does not have a major effect on the DRIS diagnosis. Nutrient sufficiency ranges derived from DRIS norms were 1.41–1.65, 0.10–0.17, 0.51–0.97, 1.16–2.12, 0.31–0.51, 0.18–0.28% for N, P, K, Ca, magnesium (Mg), and S and were 105–153, 58–110, 15–29, and 6–16 mg Kg^?1 for iron (Fe), Mn, Zn, and Cu, respectively. According to these sufficiency ranges 35, 62, 51, 75, 70, and 68% of samples were sufficient, and 4, 29, 36, 9, 10, and 22% of samples were low in N, P, K, Ca, Mg, and S, respectively. More than 50 and 2% of the guava trees selected for sampling was found to deficient in N and P, respectively. For micronutrients, 15, 6, and 7% of samples were found to be low in Mn, Zn, and Cu.     

Diagnosis and Recommendation Integrated System Norms,Sufficiency Range,and Nutritional Evaluation of Arabian Coffee in Two Sampling Periods

ABSTRACT

The objective of this work was to establish and compare Diagnosis and Recommendation Integrated System (DRIS) norms with the sufficiency range approach, and apply these methods on nutritional diagnosis of Arabian coffee, in field samples collected in summer and winter in Southern Brazil. DRIS norms and sufficiency range were established in groves with average biennial yield equal or above 3000 kg ha^{? 1}. The “t” test was used to verify the differences between the sufficiency range and the DRIS norms. The foliar concentrations of nitrogen (N), phosphorus (P), and sulfur (S) were higher in summer, and iron (Fe), and manganese (Mn) in winter. The reference values should be specific for the period of the year. There were differences in the foliar nutritional diagnosis, between the DRIS method and the sufficiency range approach. In samples during the summer analyzed with DRIS, copper (Cu), S, potassium (K), and zinc (Zn) were considered more limited nutrients and Mn, S, K, and calcium (Ca) when the sufficiency range was used.     

Diagnosis and Recommendation Integrated System for Monitoring Nutrient Status of Mango Trees in Submountainous Area of Punjab,India

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) was used to identify nutrient status of mango fruit trees in Punjab, India. Standard norms established from the nutrient survey of mango fruit trees were 1.144, 0.126, 0.327, 2.587, 0.263, 0.141% for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), and 15, 3.5, 145, 155, and 30 mg kg^?1, respectively, for zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and boron (B) in dry matter. On the basis of DRIS indices, 16, 15, 12, 17, and 16% of total samples collected during nutrients survey of mango trees were low in N, P, K, Ca, and Mg, respectively. For micronutrients, 19, 18, 12, 20, and 6% samples were inadequate in Zn, Cu, Fe, Mn, and B, respectively. DRIS‐derived sufficiency ranges from nutrient indexing survey were 0.92–1.37, 0.08–0.16, 0.21–0.44, 1.71–3.47, 0.15–0.37, and 0.09–0.19% for N, P, K, Ca, Mg, and S and 11–19, 1–6, 63–227, 87–223, and 16–44 mg kg^?1 for Zn, Cu, Fe, Mn, and B, respectively.     

Assessment of Nutritional Status of Guava Seedlings using Preliminary DRIS Norms and Sufficiency Ranges

The objective of this work was to propose preliminary Diagnosis and Recommendation Integrated System (DRIS) norms and derive critical levels and nutrient sufficiency ranges in the leaves of guava plants in commercial nursery conditions. Sixty-eight leaf samples were evaluated from fertilization trials with seedlings. In the low-yield subpopulation (84% of the population), the limiting nutrients by deficiency in descending order were nitrogen (N)> copper (Cu)>phosphorus (P) = potassium (K)> manganese (Mn)> iron (Fe) = zinc (Zn)> sulfur (S)> boron (B) = magnesium (Mg)> calcium (Ca), and the limiting ones by excess in descending order were B > Ca > Fe > Mn > S > Mg > Cu > P > Zn > N = K. The ranges of the appropriate DRIS indices were 24 to 28, 2.4 to 3.1, 21 to 29, 6 to 8, 1.9 to 2.9 and 1.9 to 2.3 (g kg^?1) for the macronutrients N, P, K, Ca, Mg and S, respectively, and 35 to 48, 4 to 15, 68 to 93, 31 to 60 and 180 to 245 (mg kg^?1) for the micronutrients B, Cu, Fe, Mn and Zn, respectively. The dry matter production of guava seedlings was associated with the nutritional status.     

Foliar diagnosis of soybean by dris

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) has proven useful in the interpretation of tissue elemental analyses for many crops, and research was undertaken to apply the same method for foliar diagnosis of soybean (Glycine max [L.] Merr.). Using a data bank in excess of 3500 tissue samples, reference values for evaluating the status of soybean with respect to N, P, K, Ca, Mg, Mn, Fe, Cu, Zn, Mo, B and Al were derived. DRIS diagnoses generally agreed with those obtained by the sufficiency range method. In addition, DRIS assessed the nutrient balance in plant tissue, and identified not only the most‐limiting element, but the order in which other elements would likely become limiting. Further, DRIS was able to diagnose plant nutrient needs earlier in the life of the crop than the sufficiency range method (5 weeks compared to 10 weeks), which would allow remedial steps to be taken earlier. Treatments indicated by DRIS to be needed gave greater yield increases than those indicated by the sufficiency range approach. Geographic differences in DRIS norms were identified, and indicate that regional derivation of diagnostic values may be necessary.     

Monitoring Nutrient Status of Ber (Zizyphus mauritiana) Fruit Trees in Semi-arid and Arid Regions of Northwest India through Diagnostic Recommendation and Integrated System Approach

The Diagnostic Recommendation and Integrated System (DRIS) was employed to interpret nutrient analyses of leaf tissues from ber fruit tree orchards grown in semi-arid and arid areas of Punjab in northwest India. The DRIS norms were established for various nutrient ratios obtained from the high-yield population and were used to compute DRIS indices, which assessed nutrient balance and their orders of limitation to yield. Nutrient sufficiency ranges derived from DRIS norms were 0.688–1.648%, 0.184–0.339%, 1.178–1.855%, 1.064–1.768%, 0.234–0.391%, and 0.124–0.180% for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) and were 55–205, 26–80, 17–33, and 5–11 mg kg^?1 for iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu), respectively. According to these DRIS-derived sufficiency ranges, 79%, 76%, 76%, 75%, 84%, and 72% of samples were sufficient, whereas 13%, 15%, 21%, 14%, 7%, and 18% of total samples were low in N, P, K, Ca, Mg, and S, respectively. For micronutrients, 84%, 85%, 77%, and 86% of samples were sufficient, whereas 6%, 3%, 8%, and 2% of samples were low in Fe, Mn, Zn, and Cu, respectively.     

Development of DRIS norms for potato in the calcareous soils of iran 1

The Diagnosis and Recommendation Integrated System (DRIS) has been proposed to determine nutrient balance in plants at different stages of growth. The DRIS index for each nutrient allows ranking of nutrients in order of their deficiency. Preliminary DRIS norms for potato (Solanwn tuberosum L.) were developed during the 1991 growing season in Damavand area located 70 km. northeast of Tehran. The soil and leaf samples at flowering stage (early tuber development stage) were collected from 50 different farms. Average concentrations of nutrients in both high‐ and low‐yielding populations were calculated. The following average foliar nutrient concentration were obtained from the high‐yielding populations: N = 5.22, P = 0.38, K = 4.20, Ca = 1.50, and Mg = 0.65 percent; and Fe = 150, Mn = 50, Zn = 40, Cu = 11, and B = 38 ppm. The average nutrient concentrations for the low‐yielding population were close to those in high‐yielding ones except for K which was 3.23 in contrast to 4.20‐percent. There was no significant relationship between different soil nutrient availability indices and yield except for K. The DRIS indices ranked K as the most limiting nutrient in the low yielding farms with only one exception. It seems high rates of N and P fertilization have created a lack of balance between these nutrients and K.

As a result of this study, the following appropriate norms for potato leaves are suggested for the calcareous soils of Iran: N = 4.5, P = 0.30, K= 5.00, Ca = 1.50, and Mg = 0.65 percent; and Fe = 150, Mn = 50, Zn = 40, Cu = 11, and B = 38 ppm. These results will be verified by field fertilizer experiments for N, P, K, Zn, and Fe which are some times deficient in potato soils.     

DRIS norms and limiting nutrients in banana cultivation in the South of Ecuador

Abstract

Foliar analysis is an effective method to diagnose the nutritional status of plants. However, the mineral concentration in foliar tissue has traditionally been evaluated by assessing the activity of each element, without considering the interactions between them. To address this, dual interactions were calculated using the Diagnosis and Recommendation Integrated System (DRIS) to identify which crop nutrients are most influential in nutrient imbalances and which are the most limiting nutrients for the nutritional status of banana crops in Ecuador. To achieve this, a regional survey of the nutritional status and its productivity levels was conducted for 188 different sites during the crop season in 2017–2018, involving banana cultivars ‘Vallery’ and ‘Williams’, from the Cavendish subgroup. The DRIS calculation method was combined with Beaufils and Jones functions. From the initial 188 foliar samples, 83 samples (representing 44% of the population) were considered to represent the high-yield reference population, with yields of 38–60 t ha^?1. The DRIS method defined the mean nutritional balance index, which was not found to be statistically correlated (p?>?0.05) with productivity, revealing that there was no significant association with the nutritional status of the plants. Specific DRIS norms were obtained and indicated that deficiencies in K, N, Ca, and Fe, and excesses in Mn, B, Cl, Zn, S, Cu, and Mg were the most limiting nutrients for banana cultivars in the south of Ecuador.     

DRIS Norms for Pêra Orange

Chemical analysis of leaves is an effective tool for detecting nutritional imbalances and providing data for fertilizer recommendations. Therefore, it is extremely important to establish criteria for interpreting these results. The DRIS (Diagnosis and Recommendation Integrated System) method is an alternative to the interpretation of results of leaf analysis as it allows the calculation of indexes for each nutrient, using its relations with others and comparing them with a reference population. Thus, we aimed to establish preliminary DRIS norms, by both Beaufils’s and Jones’s methods, and to derive critical levels and nutrient sufficiency ranges in the leaf tissue for Pêra orange, by studying a commercial crop in the growing conditions of the São Paulo state. The methods (Beaufils and Jones) differed in the limiting nutrients in the Pêra orange orchard. The use of regional norms must be prioritized because of differences between the management methods applied. In the methods used, the nutrients that had a greater number of concordant cases in decreasing order: Mn > Mg > B > N > Cu > Fe > Zn > K > P > Ca. Amplitudes related to the DRIS methods used were narrower than the conventional literature.     

Diagnosis and recommendation integrated system approach for major and micronutrient diagnostic norms for apple (Malus Domestica Borkh) under varying ages and management practices of apple orchards

Various approaches for the Diagnosis and Recommendation Integrated System (DRIS) indices were employed like Beaufil's ER, Elwali and Gascho and Jones. As per the Beaufil's approach of DRIS indices, the nutrient requirements in the initial stage of the apple tree were magnesium > nitrogen > sulfur > phosphorus > copper > zinc > iron > manganese > boron > calcium > potassium (Mg > N > S > P > Cu > Zn > Fe > Mn > B > Ca > K) and in the later stage at 40–50 years, the nutrient requirements were S > Cu > Mg > Fe > P > N > Ca > Mn > K > Zn > B, thus demanding a foliar application of magnesium salt and urea which are required in high amounts in the initial stage; however in the later stage, the yield depression was not attributed to the nutrient deficiency but rather trees' genetic make-up which destabilizes the higher yield in the period of 50 years. Nutrient sufficiency ranges for apple derived from DRIS norms were 1.91–2.24, 0.18–0.26, 1.11–1.61, 1.74–1.88, 0.30–0.33 and 0.28–0.30% for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), respectively.     

Dris calculation methods for evaluating the nutritional status of oil palm in the Eastern Amazon

This study aimed to evaluate six Diagnosis and Recommendation Integrated System (DRIS) calculation methods, including two ways to choose the nutrient ratio [F (Letzsch) or R (Nick) values] combined with three functions (Beaufils, Jones, or Elwali and Gascho), and to generate nutritional diagnoses for oil palm. A total of 144 foliar samples in 33 plots in the Eastern Amazon, Brazil, were used. Except for potassium (K) in all calculation methods, the DRIS indices showed no correlation with soil nutrients. Regardless of the formula, the nutritional balance index correlated with the productivity (significant r values) and similar diagnostics were obtained. These diagnoses were reliable according to the chi-square test (χ2), and most observed frequencies presented χ2 calculated less than χ2 tabulated. The average frequencies of samples with nutrient deficiency were 51%, 42%, 37%, 35%, 32%, 30%, 30%, 25%, 20%, 12%, and 12% for samples with nitrogen (N), boron (B), manganese (Mn), sulfur (S), K, copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), phosphorus (P), and magnesium (Mg), respectively. All tested DRIS methods may be used, and their diagnoses indicate the most common nutritional deficiencies in oil palm.     

Verifying critical values from DRIS norms in sweet cherry and hazelnut

Abstract

Previously published DRIS norms for sweet cherry and hazelnut were used to calculate DRIS indices for N, K, P, Ca, Mg, Mn, Fe, Cu, B, and Zn on over a thousand leaf sample analyses for each crop. A nutritional imbalance index (NII) was obtained by adding the values of DRIS indices irrespective of sign. The sample with the lowest NII for each crop was assumed to have “ideal”; levels of elements and these “ideal”; levels were used to create an artificial data base to determine which critical values would be most consistent with DRIS evaluations. By maintaining all but one element concentration at “ideal”; levels and artificially varying another, the concentration of a given element that was associated with the onset of severe imbalances could be identified. In addition to providing ratio‐based diagnoses, DRIS norms provide a means of independently evaluating current sufficiency ranges for elements that DRIS diagnoses as relatively deficient or excessive.     

Spatial Variability Studies in Banana for Identification of Nutrient Imbalance Using Diagnosis and Recommendation Integrated System

Spatial variability of soil properties and accompanying variability in plant nutrient concentrations in a banana growing enterprise were mapped using Geographic Information Service (GIS) technique to test the diagnostic sensitivity of Diagnosis and Recommendation Integrated System (DRIS) system. Variogram models of soil properties indicated that most of the properties exhibited definable spatial structures. The pH, available nitrogen (N), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn) and zinc (Zn) showed strong spatial dependence, whereas available phosphorus (P), potassium (K), and sulfur (S) showed moderate dependence. Most of the plant nutrients exhibited higher nugget/sill ratio indicating often mismatch between soil available nutrient and plant nutrient concentrations. DRIS indices showed high diagnostic sensitivity for N, P, K, Ca, and Fe. Application of GIS for nutrient mapping along with DRIS was found useful for identification of yield limiting nutrients in soil and plant for developing nutrient management strategies.     

Soil Nutrient Status and Leaf Nutrient Norms in Oil Palm (Elaeis Guineensis Jacq.) Plantations Grown in the West Coastal Area of India

Oil palm (Elaeis guineensis Jacq.) is a heavy feeder of nutrients and requires balanced and adequate supply of nutrients for optimum growth and yield. Information regarding soil nutrient status and leaf nutrient concentration is very much required for proper fertilizer application. Therefore, a survey was conducted for assessment of soil nutrient status and leaf nutrient concentration in 64 oil palm plantations in the state of Goa lying in the west coastal region of India. Soil pH, electrical conductivity (EC), organic carbon (OC), available potassium (K) (ammonium acetate-extractable K) (NH₄OAc-K), available phosphorus (P) (Bray’s-P), exchangeable calcium (Ca) (Exch. Ca) and magnesium (Mg) (Exch. Mg), available sulphur (S) (calcium chloride-extractable S) (CaCl₂-S), and hot water soluble boron (B) (HWB) in surface (0–20 cm depth) soil layers ranged from 4.25 to 6.77, 0.05 to 1.06 dS m^–1, 5.07 to 48.4 g kg^–1, 58.1 to 1167 mg kg^–1, 1.80 to 415 mg kg^–1, 200 to 2997 mg kg^–1, 36.0 to 744 mg kg^–1, 3.00 to 87.7 mg kg^–1 and 0.09 to 2.10 mg kg^–1, respectively. Diagnosis and Recommendation Integrated System (DRIS) norms were established for different nutrient expressions and were used to compute DRIS indices. As per DRIS indices, the order of requirement of nutrients in the region was found to be P > Mg > K > nitrogen (N) > B. Optimum leaf nutrient ranges as per DRIS norms varied from 1.64 to 2.79%, 0.36 to 0.52%, 0.37 to 0.75%, 0.89 to 1.97%, 0.35 to 0.63%, 0.89 to 1.50%, 3.10 to 13.9 mg kg^?1, 7.50 to 32.2 mg kg^?1, 35.0 to 91.1 mg kg^?1, 206 to 948 mg kg^?1, and 895 to 2075 mg kg^?1 for N, P, K, Ca, Mg, S, B, copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) respectively. On the basis of DRIS-derived sufficiency ranges, 14, 5, 11, 6, 6, 6, 8, 2, 3, 6, and 16% of leaf samples had less than optimum concentrations of N, P, K, Ca, Mg, S, B, Cu, Zn, Mn, and Fe respectively. The optimum ranges developed can be used as a guide for routine diagnostic and advisory purpose for balanced utilization of fertilizers.     

Diagnosis of nutrient imbalance in pomegranate by diagnosis and recommendation integrated system and compositional nutrient diagnosis

Abstract

A regional survey was conducted in commercial orchards of pomegranate (Punica granatum L.) in order to develop diagnostic norms and for evaluation of yield limiting nutrients in low yielding orchards. The leaf nutrient status was interpreted using Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND). The correlation structure among the nutrients was extracted by Principal Component Analysis (PCA). The departure of DRIS indices from their CND counterparts was relatively small and a highly significant positive correlation was obtained between DRIS and CND indices. The three principal components explained 59.5% of the variation in the high yielding population and the designated PCS were (N+S+Zn+Fe‐Mn‐), (N+P+Ca+Zn‐), and (K‐S+). Pomegranate is mainly grown on marginal soils with low fertility and hence more than two or three nutrients were found to be limiting yields. However, nitrogen (N) and zinc (Zn) were the most common yield limiting nutrients. The DRIS and CND indices for low‐yielding orchards are reported and discussed.     

DRIS Norms and their Field Validation in Nagpur Mandarin

ABSTRACT

Diagnosis and recommendation integrated system (DRIS) norms were computed from the data on leaf mineral composition, soil available nutrients, and corresponding mean fruit yield of three years (1999–2002), collected from the set of 57 irrigated commercial ‘Nagpur’ mandarin (budded on Citrus jambhiri Lush) orchards, representing 26 locations and 3 basalt derived soil orders (Entisols, Inceptisols, and Vertisols) rich in smectite minerals. The DRIS norms derived primarily from spring-cycle index leaves from non-fruiting terminals sampled during August to October (6–8 months old) suggested optimum leaf macronutrient concentration (%) as: 1.70–2.81 nitrogen (N), 0.09–0.15 phosphorus (P), 1.02–2.59 potassium (K), 1.80–3.28 calcium (Ca), and 0.43–0.92 magnesium (Mg). While, optimum level of micronutrients (ppm) was determined as: 74.9–113.4 iron (Fe), 54.8–84.6 manganese (Mn), 9.8–17.6 copper (Cu), and 13.6–29.6 zinc (Zn) in relation to fruit yield of 47.7–117.2 kg tree^{? 1}. Likewise, DRIS indices for soil fertility developed from dripline soil samples collected at 0–20 cm depth corresponding to similar level of fruit yield, the optimum limit of soil available nutrients (mg kg^{? 1}) was observed as: 94.8–154.8 N, 6.6–15.9 P, 146.6–311.9 K, 401.0–601.6 Ca, 85.2–369.6 Mg, 10.9–25.2 Fe, 7.5–23.2 Mn, 2.5–5.1 Cu, and 0.59–1.26 Zn. Primary DRIS indices developed on the basis of leaf and soil analysis revealed deficiency of N, P, K, Fe, and Zn. The nutrient constraints so diagnosed were further verified through fertilizer response studies carried out on a representative Typic Haplustert soil type facing multiple nutrient deficiencies, and accordingly suggested the revised fertilizer schedule.     

The DRIS for interpretation of coastal bermudagrass analysis

Abstract

Diagnosis and Recommendation Integrated System (DRIS) norms for N, P, K, Ca, Mg, and S were developed for three high‐yield Coastal bennudagrass populations that were selected from soil fertility studies that contained six rates each of N, P, and K. Norms from the high‐yield population that was based on a single yield level at a given harvest date were considered most suitable. The relative importance of criteria used to select suitable diagnostic parameters was discussed along with composition of index equations. The norms developed from Coastal bennudagrass grown on an Aquic Fragiudalf soil in south Louisiana accurately predicted yield responses to N, P and K applications at that location and to P, S, and Mg applications on Typic Paleudult soils in north Louisiana. A computer generated DRIS balance chart was designed to provide a visual interpretation of individual sets of DRIS indices.