K.S. Keram 1, S.S. Porte 1 and Brajendra Parmar 2 1 De part ment of Soil Sci ence and Ag ri cul tural Chem is try, JNKVV, Jabalpur, (M.

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1 Progressive Research 8 (Special) : (2013) Society for Sci. Dev. in Agric. and Tech. IN FLU ENCE OF SOIL TEST BASED FER TIL IZER REC OM MEN DA TION UN DER RICE-WHEAT CROP PING SE QUENCE AND ITS IM PACT ON SOIL QUAL ITY IN A ME DIUM DEEP BLACK SOIL (VERTISOL) K.S. Keram 1, S.S. Porte 1 and Brajendra Parmar 2 1 De part ment of Soil Sci ence and Ag ri cul tural Chem is try, JNKVV, Jabalpur, (M.P) 2 Di rec tor ate of Rice Re search In sti tute, Hyderabad, (A.P) Key words: ABSTRACT The present investigation were conducted during with rice and wheat in the field of Department of Soil Science and Agricultural Chemistry, J.N. Krishi Vishwa Vidyalaya, Jabalpur (M.P.) for the assessment of fertilizer recommendation and its impact on soil quality. The results indicated that inorganic fertilizer application based on targeted yield along with organic manure (FYM) i.e. IPNS approach, resulted in higher grain yield 4.04 and 6.94 t/ha of both rice and wheat, respectively thereby showing superiority to GRD in terms of total uptake in biomass while STCR approach was more superior in soil fertility build-up in rice and wheat. The soil respiration was found to be more in plots receiving no fertilizer, GRD and STCR approaches, with high level of The ideal state of biological activity was recorded in IPNS approaches, which was due to higher CO2 sequestration rate (54.60 Mg/ha) as compared to other treatments like GRD and STCR approach. Rice-wheat, STCR, Soil fer til ity sta tus, soil qual ity in dex. Rice and wheat form the staple food for more than one billion people and a livelihood for millions of workers or farmers all over the world. Intensive cultivation, growing of exhaustive crops, use of imbalance and inadequate fertilizers accompanied by restricted use of organic manures and biofertilizers have not only made the soils deficient in the nutrients, but also deteriorated the soil heath resulting in decline in crop response to the recommended dose of fertilizer. Non-judicious enhancement of the fertilization further worsened the situation. Under such a situation, integrated plant nutrient system (IPNS) has assumed a great importance and has vital significance for the maintenance of soil productivity. Organic manures, particularly FYM, not only supply macronutrients but also meet the requirement of micronutrients, besides boosting yield and improving soil health. The soil quality, soil health and soil condition are interchangeable as all describe the soil s ability to support crop growth. Soil quality indicators are needed to facilitate the measurement of soil quality. The indicators of soil physical, chemical and biological properties, reflects soil functions, are easy to measure for a variety of users and under various field conditions and respond to changes in climate and management. Key soil quality indicators are soil texture, bulk density, aggregation, available water capacity, ph, EC, NPK reserve, soil organic carbon (SOC) and microbial biomass. Restoration of soil health through SOC management is a major concern for Indian soils. Soil productivity can certainly be lost through erosion, nutrient mining or other processes such as salinization, sodification, compaction and waterlogging. The linkage between soil productivity and soil quality is apparent when change in soil is attributed to assess soil quality are linked to causes of productivity loss. Keeping this in view, the present investigation were undertaken to evolve soil test based fertilizer recommendations to quantify the net changes in soil fertility (N, P and K) and thereof nutrient mining under different approaches of nutrient recommendations and to study the soil quality index vis-à-vis different fertilizer recommendations practices under rice-wheat cropping MATERIALS AND METHODS The field experiment was conducted on rice and wheat crops during at the Research Farm of the Department of Soil Science and Agricultural Chemistry, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur. The experimental soil was medium black belonging to Kheri series of fine montmorillonitic hyperthermic family of Typic Haplustert and had ph of 7.0, electrical conductivity 0.23 ds/m (1 : 2.5 soil : water ratio) and

2 Keram et al., 303 organic carbon 7.0 g/kg. Treatments schedule for rice-wheat cropping sequence comprising of T 1 -control, T 2 -general recommended dose (GRD), T3-soil test crop response (STCR) recommendation for target yield-i (T.Y.-I), T4-STCR for T.Y.-II, T5- integrated plant nutrient system (IPNS) approach-i : STCR for T.Y.-I + 5 t FYM/ha, T6-IPNS approach-ii : STCR for T.Y.-II + 5 t FYM/ha. There were six treatments replicated four times in a randomized block design for both the crops. Treated seeds of rice (JR 201) and wheat (GW 273) were dibbled in rows at proper spacing in the first week of July and November 2007, respectively after basal application of fertilizers as per treatments. The soil samples were collected before sowing and after the harvest of both rice and wheat crops during with the help of a tube auger (stainless steel) from each plot at 0-15 cm soil depth. Basic soil parameters were estimated by using standard laboratory procedures (1). To compute fertilizer doses for any yield target based on soil test value fertilizer adjustment equations were used {Table 1(a), (b) and (c)} as per procedure of (2). The targeted yields for rice were 3 and 4 tonnes/ha and for wheat 4.5 and 6 tonnes/ha were fixed. 100% NPK dose for rice and wheat crop was given. The fertilizer materials used were urea, single super phosphate and muriate of potash. Full dose of P and K and half dose of N were applied and mixed thoroughly with soil at the time of sowing. The remaining half dose of N was top-dressed in two splits at tillering stage and boot stage. The crops rice and wheat were cultivated adopting proper package of practices. All climatic conditions were favourable for growth and development of both crops. The rice crop was grown as rainfed while wheat was grown under irrigated condition. The grain yields of rice and wheat were recorded at the harvest of each crop on maturity for each treatment. The soil and plant samples were analysed by standard laboratory procedure. Thus, the analysis of variance was carried out using the randomized block design as described by (3). RESULTS AND DISCUSSION on nutrient uptake (N, P and K) : The aim of rational fertilizer application is to provide the plant with an adequate supply of nutrients at the time it needs and utilizes them most towards grain production. It is obvious that the total uptake is the function of nutrient concentration and yield and dealt data is the testimony of this fact. These characteristics relations go hand to hand in same glove. The test technology of fertilizer recommenda- tion i.e. STCR technology for T.Y. 4 t/ha in paddy and T.Y.6 t/ha in wheat, combined with 5 t FYM/ha, each has shown cutting edge over convectional technology of fertilizer recommendation in terms of yield, removal and residual effect of nutrients (N, P and K). The relative distribution of these nutrient uptake values in rice and wheat indicates that addition of FYM to inorganic fertilizer enhances the nutrient uptake which is apparent on comparison of treatments pairs T 3 T 5 and T 4 T 6 (Table-2). (4) confirmed that nutrient uptake (N, P and K) values were of higher order in FYM treated plots and these further improved with graded levels of nutrient application (4) corroborate the similar findings, under rice-wheat cropping on net change in soil fertility variable (N, P and K) under rice-wheat cropping sequence : Under rice-wheat cropping sequence, there were positive changes (build-up) in post-harvest soil test values (PHSTV)-N and PHSTV-K in treatment T 4, as compared to the other treatments (Table-3). While in case of PHSTV-P status, depletion was observed in all treatments from its initial soil test values (ISTV)-P. (5) reported similar findings who observed that application of only 100% N resulted in a decrease in the available P contents. Similar results were reported by (6). Table-1(a): Basic data for targeted yield equation of rice and wheat. Parameter Nutrient requirement (kg/q) Nutrient contribution from soil (%) Nutrient contribution from fertilizer (%) N P 2 O 5 K 2 O N P 2 O 5 K 2 O N P 2 O 5 K 2 O Rice Wheat Note: Composition of FYM: N 0.92%, P 2 O % and K 2 O 0.90%

3 304 Influence of soil test based fertilzer recommendation under rice-wheat cropping sequence Table-1(b): Soil test value for rice-wheat cropping Crops Available soil nutrient N P K Rice Wheat Table-1(c): Fertilizer adjustment equations used for rice-wheat cropping Rice Wheat F N = 4.25 T SN F N = 4.40 T SN F P 2 O 5 = 3.55 T SP F P 2 O 5 = 4.00 T SP F K 2 O = 2.10 T SK F K 2 O = 2.55 T SK where, F N - Fertilizer nitrogen F P 2 O 5 - Fertilizer phosphorus F K 2 O - Fertilizer potassium T - Desired yield target (q/ha) SN - Available soil nitrogen SP - Available soil phosphorus SK - Available soil potassium Relationship between observed post-harvest soil test values and predicted soil test values : An attempt was made to evolve relationship between post-harvest soil test value and predicted soil test value, under rice- wheat cropping The characteristic functional relation is represented by linear equations. These are : Y = X (R 2 = ) for N, Y = 1.064X (R 2 = *) for P and Y = X (R 2 = ) for K, where Y is predicted, post-harvest soil test values and X is observed post-harvest soil test values. In case of soil P, there was significant association between predicted and observed post-harvest soil test values (Table-4). Further, a wayward behavior of this nutrient could be due to variable nutrient release efficiencies from different sources i.e. soil, inorganic fertilizer and organic manure and their utilization by plants (7) reported that, in Typic Halpludalfs, though recommendation based fertilizer doses are somewhat higher initially, but if this approach is adopted continuously, there is build-up of nutrients (NPK) in the soil which results in reduction in fertilizer doses with time for attaining targeted yield, under maize-wheat cropping on nutrient mining of rice and wheat : The highest N mining was recorded in treatment-t 6 (IPNS approach), K mining in treatment-t 3 (STCR approach) and P mining in treatment-t 1 (control) in rice (Table-5). The data further revealed that the highest N mining in treatment-t 3 (STCR approach), P mining in treatment-t 1 (Control) and K mining in treatment-t 2 (GRD) were noted in wheat. It indicates that, the nitrogen and potassium efficiencies are accelerated due to addition of FYM in rice and wheat. These findings are further confirmed by Kumar and Prasad (2003) on clay loam soil, who recorded similar observations. on soil quality index under rice-wheat cropping sequence : As per guideline of Soil Quality Test Kit, proposed by USDA (1999) the data given in table-6 revealed that the soil belongs to non-saline and neutral category and it has more than 45% clay with ideal bulk density. Similar observations were recorded by (9) in Vertisols. The soil respiration was more in plots receiving no fertilizer, followed by GRD and STCR approaches, with high level of microbial activity, whereas ideal state of biological activity was recorded by IPNS approaches. This variation in soil respiration could be due to temperature, moisture and edaphic factors. It is also affected by the nutrient status of soil and cultural Table-2: on total nutrient uptake in biomass of rice and wheat. Rice Wheat Treatments Total uptake Treatments Total uptake N P K N P K T 1 : Control T 1 : Control T 2 : GRD T 2 : GRD T 3 : T.Y.3 t/ha T 3 : T.Y.4.5 t/ha T 4 : T.Y.4 t/ha T 4 : T.Y.6 t/ha T 5 : T.Y.3 t/ha + 5 t FYM/ha T 5 : T.Y.4.5 t/ha+ 5 t FYM/ha T 6 : T.Y.4 t/ha + 5 t FYM/ha T 6 : T.Y.6 t/ha + 5 t FYM/ ha Mean SEm± utocd (5%)

4 Keram et al., 305 Table-3: on net change in soil fertility variables (N, P and K) in rice-wheat cropping sequence Treatments Initial soil test values of rice (ISTV) Post-harvest soil test values after wheat (PHSTV) Buildup(+)/Depletion (-) N P K N P K N P K T (-1) 8 T T T (-1) 57 T (-1) 3 T (-2) 13 Mean N = Available soil nitrogen, P = Available soil phosphorus and K= Available soil potassium Table-4: Relationship between post-harvest soil test values observed and predicted soil test values under rice-wheat cropping Parameters Regression equations Co-efficient of predictability (R2) Nitrogen Y=0.929X Phosphorus Y=1.046X * Potassium Y= X Table-5: on nutrient mining in rice and wheat. Treatments Total nutrient added Total nutrient removal Nutrient mining (%) Rice Wheat Rice Wheat Rice Wheat N P K N P K N P K N P K N P K N P K Control GRD STCR approach: I STCR approach: II IPNS approach : I IPNS approach : II Mean Note : STCR approach: I = Lower yield target (t/ha): Rice-3 and Wheat-4, STCR approach: II = Higher yield target (t/ha): Rice-4.5 and Wheat-6, IPNS approach: I = STCR approach: I + 5 t FYM ha, IPNS approach: II = STCR approach: II + 5 t FYM ha Table-6: Soil quality index card of Vertisols under rice-wheat cropping Nutrient Soil quality parameters management practices ph EC (ds/m) Bulk density (g/cm) Control Neutral Non-saline Ideal GRD STCR approach: I STCR approach: II IPNS approach : I IPNS approach : II Source : Soil Quality Test Kit (1999) Neutral Neutral Neutral Neutral Neutral Non-saline Non-saline Non-saline Non-saline Non-saline Ideal Ideal Ideal Ideal Ideal Soil respiration (g/kg/week) 3.95-High level of 1.81-High level of 1.72-High level of 1.59-High level of 1.25-Ideal state of biological activity Ideal state of biological activity.

5 306 Influence of soil test based fertilzer recommendation under rice-wheat cropping sequence Table-7: on soil organic carbon (SOC) density and stock (0-10 cm) under rice-wheat cropping sequence Treatments SOC density (g/m) SOC stock (Mg/ha) CO 2 SOC change Initial Final Initial Final sequestration (g/m 2 /year) (Mg/ha) T T T T T T Mean practices such as inorganic fertilizer or FYM application and various biological, microbial and soil activities which regulates the CO 2 evolution rates. Similar findings were reported by (10). on soil organic carbon (SOC) density and stock (0-10 cm) under rice-wheat cropping sequence The aim of comprehensive studies is to quantify SOC density, SOC stock and SOC changes, under rice-wheat cropping sequence under different nutrient management practices over a period of time for sustainable productivity. The highest initial SOC density (9710 g/m 2 ) and stock (97.10 Mg/ha) at 0-10cm depth was observed in IPNS approach (T 6 ), as compared to other nutrient management practices (Table-7). Consequently, the same treatment (T 6 ) recorded maximum SOC change 1500 g m-2/year, due to higher CO 2 sequestration rate (54.60 Mg/ha) as compared to other treatments like GRD and STCR approach. This could be due to the capacity of the soil for storing organic carbon, depending on silt+clay, moisture, nutrient supply, ph, mineralogy and landscape. Incomplete and slower rate of decomposition of organic matter also affect the SOC density and stock. Singh et al., (2008) reported that, under rice-based cropping system with RDF+FYM was more efficient for enhancing SOC density (43.2%) and stock (40.6%) and in sequestrating CO 2 (30.32 t/ha). Similar findings were reported by Aulakh et al., (2001) in Typic Ustochrepts. REFERENCES 1. Jackson, M. L. (1967). Soil Chemical Analysis. Prentice Hall of India. New Delhi, pp Ramamoorthy, B., Narsimham, R. L. and Dinesh, R. S. (1967). Fertilizer application for specific yield targets of Sonara-64. Indian Farm., 17: Gomez, K. A. and Gomez, A. A. (1984). Statistical procedure for agricultural research IInd edition. John Wiley and Sons, New York. Inc. pp Sharma, M. P., Wali, P. and Gupta, J. P. (2003). Long term effect of chemical fertilizers on rice-wheat productivity and fertility of an Inceptisol. Annls. Agric. Res., 24: Singh, D., Rana, D.S. and Kumar, K. (1998). Phosphorus removal and available P balance in Typic Ustocrept under rice-wheat cropping and long term fertilizer use. J. Indian Soc. Soil Sci., 46: Singh, M., Singh, R. and Dixit, M.L. (2004). Soil test based fertilizer and FYM application for specific yield in paddy-wheat 69th Annual Convention: Oct Suri, V.K. and Verma, T. S. (1999). Targeted yield concept for efficient and economic fertilizer use in a maize-wheat cropping system and build-up of fertility in a Typic Hapludalf. J. Indian Soc. Soil Sci., 47: Kumar, V. and Prasad, B. (2003). Integrated nutrient management for rice-wheat system. J. Res. Birsa Agril. Uni., 15: Khan, J.A., Kurchania, S.P. and Agrawal, S.B. (2004). Yield maximization in rice-wheat sequence through agronomic manipulation. National Seminar-cum- Workshop on Challenges for enhancing riceproduction in fragile environments Oct Chaudhury, J., Mandal, U. K. and Sharma, K. L. (2005). Assessing soil quality under long-term rice-based cropping system. Comm. Soil Sci. Plant Anal., 36: Singh R.K., Singh, S. K.and Tarafdar, J. C. (2008.) Influence of cropping sequence and nutrient management on soil organic carbon and nutrient status of Typic Rhodustalfs. J. Indian Soc. Soil Sci., 56: Aulakh M. S., Khera, T. S. and Doran, J. W. (2001). Managing crop residue with green manure, urea and tillage in a rice-wheat rotation. Soil Sci. Soc. Ame. J., 65: